Welcome! I am an Assistant Professor of Political Science in the School of Public and International Affairs at the University of Cincinnati. I am also a Research Affiliate with the Portman Center for Policy Solutions.
I study American legislatures, with a particular focus on Congress, campaigns and elections, and identity. I specialize in quantitative methods and use big data, machine learning, and causal inference in my research. My work is published in outlets such as Political Research Quarterly, PS: Political Science & Politics, and State Politics & Policy Quarterly.
I received my Ph.D. in Political Science from the University of Virginia in 2025. Before UVA, I earned a B.A. in Politics and International Affairs, with a minor in Poverty Studies, from Furman University.
Publications
I’m Coming Out! How Voter Discrimination Produces Effective LGBTQ Lawmakers
Jacob M. Lollis and Mackenzie R. Dobson.
PS: Political Science & Politics, 2025.
PDF DOI Replication
Abstract
Are LGBTQ legislators effective lawmakers? We build on theories that link voter discrimination to legislative effectiveness by arguing that voters’ biases against LGBTQ candidates narrow the candidate pool, leading to the election of only the most experienced and qualified LGBTQ candidates. As a result of this electoral selection effect, we expect that LGBTQ legislators will be more effective lawmakers than their non-LGBTQ counterparts. To test this, we combine data on state legislators’ LGBTQ identification with their State Legislative Effectiveness Scores (SLES). Our findings reveal that LGBTQ legislators are meaningfully more effective than non-LGBTQ legislators. To link our findings to voter discrimination, we leverage over-time variation in discrimination toward LGBTQ individuals. Across four tests, we consistently find that LGBTQ lawmakers elected in highdiscrimination environments are more effective than those elected from less discriminatory environments.
Race, Contact Effects, and Effective Lawmaking in Congressional Committee Hearings
Jacob M. Lollis
Political Research Quarterly, 2025.
PDF DOI
Abstract
Though there is strong evidence that nonwhite lawmakers introduce more racially salient legislation than white lawmakers, it is less clear whether race is a significant predictor of other legislative behavior. Given mixed findings in existing research, lawmakers’ actions in committee offer a new test of how race shapes legislative behavior. I develop new, original measures identifying race references in more than 1.4 million congressional committee hearing statements. I find that nonwhite lawmakers discuss race more frequently than white lawmakers in hearings, though white lawmakers are more likely to mention race in racially diverse hearings due to contact effects. Using a novel measure of race-issue bills, I demonstrate that lawmakers’ race statements in hearings are linked to policy representation. These findings explain how racial diversity in legislatures affects legislative speech and policy representation.
Are Workers Effective Lawmakers?
Jacob M. Lollis
State Politics & Policy Quarterly, 2024.
PDF DOI Replication
Abstract
Are workers effective lawmakers? Throughout American history, some politicians and elites have argued that white-collar Americans are more qualified than working-class Americans to govern. To date, however, we know relatively little about the legislative effectiveness of working-class lawmakers. I develop a theory of class-based electoral selection that links class-based discrimination in elections to legislators’ performance in office. I argue that working-class candidates face class-based biases in elections that make it more difficult to emerge and successfully win elective office. As a result, I expect the working-class candidates who do become lawmakers to be equally or more effective than their white-collar colleagues. To test these expectations, I create a data set merging the occupational background of more than 14,000 individual state legislators with their state legislative effectiveness score (SLES). The resulting data set includes more than 50,000 state legislator-term specific observations. Consistent with my expectations, I find that working-class lawmakers do not underperform white-collar lawmakers. Further, I provide evidence that, across various models and specifications, the gap between working-class and white-collar legislators’ effectiveness is negligible.
Nothing to See Here: Republican Congressional Members’ Twitter Reactions to Donald Trump,
C. Danielle Vinson and Jacob M. Lollis
Congress & The Presidency, 2023.
DOI Replication
Abstract
How do co-partisans respond to the President on Twitter? This article examines whether and how Republican legislators reacted to President Trump in five instances when he broke with Republican Party policy positions or norms. We theorize that legislators’ electoral environment, constituency, and identity shape their response to the president, and we test our hypotheses using nearly 2,500 hand-coded tweets from Republican legislators between 2018-2020. The overwhelming reaction by Republican legislators to Trump’s actions was to ignore him. When members did react to the president, their response was primarily driven by their electoral environment and identity. Those from the most Trump supportive districts supported the president, and retiring members were most likely to oppose him. Male legislators were much more likely to support and oppose the president, while female legislators mostly ignored him. And, if they reacted, the most ideologically extreme Republicans were more likely to support than oppose the president. The implications of these findings are troubling. Even when President Trump violated traditional norms or deviated from long held party positions, his congressional co-partisans remained silent, occasionally offering support but rarely opposition.
Working Papers
Congressional Attention to Abortion after Dobbs: How
Representational and Electoral Incentives Selectively
Shape Issue Attention
Jacob M. Lollis and Mackenzie R. Dobson
Status: Under Review
Paper
Abstract
Landmark Supreme Court rulings can significantly alter policy, expand or restrict rights, and reshape public opinion. Yet whether—and how—such rulings shift congressional attention on specific issues remains unclear. We examine this question in the case of Dobbs v. Jackson Women’s Health Organization (2022), which eliminated the federal constitutional right to abortion. We argue that, after Dobbs, legislators increased attention to abortion selectively, only when two incentives aligned: gender-based representational considerations and party-based electoral incentives. These incentives converged for female Democrats. Female Republicans, however, faced electoral risks in foregrounding abortion, and male legislators faced weaker gender-linked representational incentives. Using nearly 1.6 million statements from U.S. House committee hearings, we treat the draft opinion leak (May 2, 2022) as a treatment in difference-in-differences models comparing pre- and post-leak attention by party and gender. Pre-treatment trends show no systematic differences. After the leak, female Democrats increased abortion-related references by two percentage points relative to female Republicans, with no change among male legislators. Elevated attention to abortion among female Democrats persisted through the 119th Congress (2025). We also show that, across six non- abortion policy areas, the same gender- and electoral-based patterns do not emerge, providing additional evidence that Dobbs is the primary driver of the observed increase in abortion attention. Our results are robust to an alternative measure of issue attention: cosponsorship of abortion-related bills. These findings indicate that legislators’ responses to Dobbs were selective and shaped by gender- and electoral-based incentives.
Learning in Committee: How Racial Diversity Shapes Speech, Evidence Use, and Substantive Representation in Congress
Jacob M. Lollis
Status: Under Review
Paper
Abstract
Although increased racial diversity has expanded congressional attention to race, we know little about how committee diversity shapes interactions between nonwhite and white legislators—or whether those interactions alter behavior. I argue that in racially diverse committees, white Democrats learn from nonwhite colleagues, leading them to make more evidence-based claims when discussing race. To test this expectation, I combine large-scale text classification with a detailed content analysis of more than 11,000 race-based committee hearing statements and 87,000 full bill texts from the 105th–117th Congresses. Using a within-legislator identification strategy, I find that white Democrats are more likely to reference evidence when discussing race in diverse committees and to cite the same sources as their nonwhite colleagues. I also demonstrate that race-based expertise facilitates substantive representation, as legislators with such expertise are more effective at advancing race legislation. These findings demonstrate that descriptive representation fosters substantive representation in part through identity-based learning in legislative committees.
Measuring the Concentration of Legislative
Effectiveness: Evidence from U.S. State Legislatures
Jacob M. Lollis and Todd Makse
Status: Under Reveiw
Paper
Abstract
Research on legislative effectiveness has largely emphasized individual-level traits associated with policymaking success. We shift attention to how lawmaking success is distributed within and across legislatures by introducing a new measure—the Effective Legislator Ratio (ELR)—which captures the share of legislators in a chamber who consistently account for policy successes. We argue that two features of legislatures’ institutional design—the centralization of policymaking opportunity and the centralization of agenda power—shape whether effectiveness is concentrated among a small set of lawmakers or more broadly shared, and that this concentration, in turn, alters legislators’ behavior. We test our argument in U.S. state legislatures and report three primary findings. First, the distribution of policy success varies widely across state legislative chambers and is most concentrated for consequential legislation. Second, variation in policymaking opportunity (e.g., chamber size and bill introduction limits) is more strongly associated with the distribution of policy success than variation in agenda power (e.g., agenda control and leadership powers). Third, new legislators adapt their cosponsorship strategies in response to the concentration of effectiveness in their chamber. The ELR is a flexible measure that can be applied to most legislatures, enabling comparative analyses of the concentration of lawmaking success and its consequences.
Why Citizens Dislike Professional Legislatures: White-Collar Government and Policymaking for the Wealthy
Mackenzie R. Dobson, Jacob M. Lollis, Jeffrey J. Harden, and Justin H. Kirkland
Status: Under Review
Paper
Abstract
The steady professionalization of American state legislatures has created a key tension in political representation: citizens disapprove of professionalized legislatures, on average, yet those legislatures are best equipped to represent their policy preferences. We explain this paradox by arguing that citizens’ disapproval stems from distrust of white-collar legislators—who are overrepresented in professionalized chambers—and their policy priorities, rather than from opposition to institutional reforms that enhance legislative capacity. Using data from a pre- registered conjoint experiment and temporal observational analyses, we find that citizens do not oppose the institutional expansion of legislative capacity. Rather, they react negatively to representation from white-collar lawmakers, whom they associate with professionalized legis- latures. Further, we demonstrate that this opposition is justified; income inequality and poverty have increased with professionalism over time. These findings challenge existing accounts by suggesting that disapproval of professionalism is a rejection of governing by economic elites—not of reforms intended to support legislative capacity.