Senate Majority Leader Mitch McConnell (R-Ky.) smiles after announcing Thursday the release of the Republican health-care bill, which represents the party’s long-awaited attempt to scuttle much of President Barack Obama’s Affordable Care Act. (J. Scott Applewhite/Associated Press)

Senate Majority Leader Mitch McConnell (Ky.) and the GOP leadership are scrambling this week to corral 50 out of 52 Republican votes for an historically unpopular health-care bill. Why did so many House Republicans already vote for a bill that large majorities in every state detest? And why are their Senate colleagues considering walking the same plank, given the electoral risk?

In our book, “Representing Red and Blue: How the Culture Wars Change the Way Citizens Speak and Politicians Listen,” we find that thumbing one’s nose at public opinion might spell trouble for elected Democrats. But Republicans typically have much less to fear, because most GOP voters don’t expect — or even want — their representatives to follow the public will.

Republicans prefer ‘trustee’ representation

According to several years of nationally representative survey data, about two-thirds of Americans believe that elected representatives should “try their hardest to give the people what they want.” Remarkably, however, Republican voters are between 20 and 30 points less likely than their Democratic counterparts to agree. Moreover, people represented by a Republican member of Congress are almost 20 percentage points less likely to perceive their member as behaving that way, regardless of their own party identification.

It’s not as nefarious as it sounds. Republican voters, whether they consciously realize it or not, are more comfortable with what political scientists call “trustee-style representation,” whereby representatives use their own principled judgment when casting votes. In contrast, the “delegate style” binds legislators to constituent demands. Many Republicans — voters and lawmakers alike — cherish their principles more than they do the whims of a mostly uninformed and inattentive mass public.

Why the partisan divide?

As with so much, the U.S. culture wars drive this partisan representation divide.

First, members of groups that comprise the Republican base seem especially averse to delegate-style public overtures. Even after taking account of other forces that might shape citizens’ views of lawmakers, we found that traditionalistic Christians are 23 points less likely than seculars to say that representatives should “give the people what they want.” Instead, they should “stick to their principles, no matter what the polls might say.”

Second, those most inclined to favor traditional power relationships in the home or to oppose egalitarian causes are 32 and 29 points less likely, respectively, to respect public opinion in this way.

Third, when Republicans think their representatives are getting soft, they try to hold them accountable. In surveys, we asked respondents to tell us not only what kind of representation they wanted but also the kind they thought they were actually getting. Democrats proved 23 points less supportive of their representatives when they perceived them paying too little attention to public opinion. In contrast, Republicans were up to 50 percentage points less supportive when they saw them paying too much attention.

Fourth, judging from legislative roll-call data since 1985, Republicans in Congress have been considerably less likely than Democrats to follow their constituents’ policy preferences — a tendency that has grown over time. We found that the ideological convergence between voters and legislators is more than three times greater among Democratic legislators than among Republicans.

Here’s what that means for the promise to repeal and replace Obamacare

These stark partisan differences suggest that Republicans could well buck broad public opinion and vote for an unpopular Senate health-care deal. Granted, polling on the House bill has revealed stronger support among Republicans than Democrats for repealing and replacing Obamacare. But judging from our research, if Republicans were to break their party’s seven years of promises to repeal Obamacare just because the polls have changed, many GOP voters would consider it a rudderless sellout, which could carry greater political risk.

For Republican lawmakers, effective pandering to constituents may have taken on a new meaning: You can charm your constituents by ignoring majority preferences, in devotion to your principles.

It remains to be seen whether the Republican Senate will pass its health-care plan this week. But it’s likely to secure the votes of at least 48 of 52 Republicans. And Republicans who vote for it will probably not suffer any meaningful consequence from GOP voters for doing so.

David C. Barker is the incoming director of the Center for Congressional and Presidential Studies and professor of government at American University. Follow him on Twitter @barkerccps.

Christopher Jan Carman is the Stevenson Professor of Citizenship at the University of Glasgow and the academic dean of the University of Glasgow – Nankai University Joint Graduate School. Follow him on Twitter at @cjcarman.

Together they are the authors of “Representing Red and Blue: How the Culture Wars Change the Way Citizens Speak and Politicians Listen” (Oxford University Press, 2012).