After months of trying to work with congressional Republicans to repeal the Affordable Care Act, or to pass anything at all, President Trump met and negotiated with Democratic leaders: Senate Minority Leader Charles E. Schumer (N.Y.) and House Minority Leader Nancy Pelosi (Calif.).

Reportedly, the Republican leaders, Senate Majority Leader Mitch McConnell (Ky.) and House Speaker Paul D. Ryan (Wis.), were frustrated by this overture. But presumably, if Republicans had moved legislation along, such a meeting wouldn’t have been necessary. And indeed, in the end, their effort failed.

Why do Republicans struggle to govern, despite controlling Congress and the White House?

Republican rhetoric suggests that their partisans are more ideologically consistent than Democrats. But that obscures important policy differences among Republican activists and elected officials – differences that undermine Republicans’ capacity to legislate.

There’s a difference between partisans’ policy attitudes and their ideology

Think of parties as extended networks of party activists who all want something from government. Activists may not share the same goals, but they develop an ideology — or common party brand — that allows each coalitional faction to pursue its individual goals with an alliance, and that connects them to voters.

Recent research shows that Republicans are best viewed as an ideological group dedicated to a principled commitment to limited government and traditional social arrangements. In contrast, Democrats are a loosely connected coalition organized around support for a more active government, especially initiatives designed to alleviate discrimination and inequality.

Democratic and Republican elites also talk differently about politics. Democratic speeches, campaign advertisements and claims of electoral mandates are all defined largely by appealing to concrete policies and programs. Republicans speak in ideological abstractions, framing their agenda not by defining policy goals but by talking about “freedom,” “small government” and “American individualism.”

We wondered why. Could Republican messaging be designed to obscure policy differences among Republican activists and elected officials?

Perhaps Republican elites speak abstractly because the broad language of “limited government” and “freedom” that appeals to conservative sensibilities successfully unites actors who do not agree on policy. On the other hand, perhaps Democratic messaging focuses on specific policies because, although they are considerably more demographically diverse, Democratic leaders nonetheless share a central ideological goal: using government programs to ameliorate social ills.

This is what we learned from surveys of party activists

To test these theories, we used the Convention Delegate Study — surveys of delegates to the national party conventions in 2000 and 2004 — to examine party attitudes. We looked at convention delegates because they are party activists who shape party platforms and mass public opinion.

We examined Democratic and Republican delegates’ attitudes toward 10 issues in each year that covered the major policy domains in U.S. politics. Specific issues included attitudes toward government spending across a variety of programs, government assistance to minorities, environmental regulation, the military and abortion. Then we tested how unified each party was by using an existing measure that assesses how well a person’s identification as a “liberal” or “conservative” matches his or her policy attitudes, along with several other statistical tests of our theory.

We focus on the proportion of delegates within each party whose policy attitudes align with his or her party identification. For example, among Democrats, an “ideologically correct” response to a question asking if government unemployment spending should be increased, decreased or remain the same would be “increased,” as the ideologically “liberal” preference is to increase government spending on social programs. The opposite is true for a Republican delegate. The graph below shows the results of this analysis in the year 2000; we show only the results for the year 2000 for clarity.

The Democratic coalition is significantly more ideologically unified than the Republican coalition

The results are stark. More than 80 percent of Democrats offered an ideologically “correct” response to six or more of the 10 policy issues we examined; only 60 percent of Republicans responded in a way that was consistent with their party’s ideology. That 20-point gap remained about the same when we raised the standard from six to eight ideologically “correct” responses: About 55 percent of Democrats and only about 32 percent of Republicans met that standard.

What about individual policy issues? Consider, for instance, public school spending. Democrats were nearly unanimous in preferring that the federal government increase spending on education. By contrast, the Republican coalition was divided. In fact, more Republicans wanted federal spending increased than wanted it decreased, by 40 percent to 30 percent.

What about a hot-button cultural issue such as abortion? Here, Democrats almost uniformly adopted a “liberal” position: 80 percent of the Democratic convention delegates responded that abortion should be “always legal,” and more than 90 percent offered an ideologically “correct” response, which included the belief that abortion should be legal if the woman would have difficulty caring for the child. In contrast, only 40 percent of Republicans provided an ideologically congruent answer that abortion should never be permitted or that the procedure should be permitted only if the health and life of the woman is in danger.

In other words, Republicans are less unified than one might guess. The GOP unites under one “conservative” ideological banner activists and elected officials with diverse policy attitudes, some of whom support parts of the social welfare state and liberal social policies.

We find similar trends in 2012 and 2016

Using the 2012 and 2016 American National Election Study, we mimicked the activist sample by examining the attitudes of the most participatory citizens in the mass public, defined here as individuals who reported engaging in at least one campaign activity beyond voting during the election year. We found nearly identical results among these politically engaged citizens.

The graph below shows attitudes toward the same 10 issues we examined earlier, only this time we are analyzing the engaged mass public sample in 2016. The results mirror those found earlier among convention delegates: Democrats are considerably more unified in their policy attitudes than Republicans.

On a few issues, Republicans in 2016 were more unified than Democrats. Those include such racial questions as attitudes toward assistance to African Americans and affirmative action. They were united on a few other issues that we examined beyond the original 10, including such foreign policy questions as whether the United States should send troops to Syria to fight the Islamic State.

However, just as with our previous sample, Democrats are more ideologically cohesive than Republicans overall, including in their attitudes toward immigration and the specific issue of whether people who were brought to the United States illegally as children should be permitted to remain in the country. The fact that both parties’ faithful support something like the Deferred Action for Childhood Arrivals (DACA) program — even when, as with Republicans, it’s not consistent with party ideology — points to why Congress may be able to respond to the president’s call to legislate a solution.

Health care — not one of the issues included in the graph — is particularly noteworthy because it divides both parties equally. A majority of Democrats would rather see health care provided by the government than by private companies, but partisans’ 2016 attitudes seem to reflect the party’s internal debate over the merits of a single-payer system. Similarly, the fractious Republican floor debates over repealing the Affordable Care Act can be seen in these survey data, explaining why the GOP repeal effort failed — and why Republicans seemed so eager to pass a last-ditch effort quickly.

The president has made ideologically charged promises to dismantle elements of the welfare state, curtail legal immigration and significantly reform the federal tax code. Our data suggest that Republicans are unlikely to make much progress on these priorities this year. Legislating will continue to be difficult for Republicans in Congress as long as deep disagreements on major policy issues continue to divide GOP elites and their activist base.

Bob Lupton is an assistant professor in the political science department at the University of Connecticut. He studies the role of core values, ideology and partisanship in public opinion and voting behavior, mostly in the American context. Find him on Twitter @GoBlueBob7.

William M. Myers is an assistant professor of political science and international studies at the University of Tampa. He specializes in judicial politics and political behavior.

Judd Thornton is an assistant professor in the political science department at Georgia State University. He specializes in public opinion and political behavior.