I read an article recently that tried to explain why Republicans oppose the individual health care mandate even though it used to have wide support among Republicans and even was officially proposed Republican legislation.
Why Republicans Oppose the Individual Health-Care Mandate : The New Yorker
In short, the reason is not so much carefully considered reasoning, but politics.
The article cites several studies that reveal this phenomenon:
Supporting and aligning with the party wins out over good policy.Geoffrey Cohen, a professor of psychology at Stanford, has shown how motivated reasoning can drive even the opinions of engaged partisans. In 2003, when he was an assistant professor at Yale, Cohen asked a group of undergraduates, who had previously described their political views as either very liberal or very conservative, to participate in a test to study, they were told, their “memory of everyday current events.”
The students were shown two articles: one was a generic news story; the other described a proposed welfare policy. The first article was a decoy; it was the students’ reactions to the second that interested Cohen. He was actually testing whether party identifications influence voters when they evaluate new policies. To find out, he produced multiple versions of the welfare article. Some students read about a program that was extremely generous—more generous, in fact, than any welfare policy that has ever existed in the United States—while others were presented with a very stingy proposal. But there was a twist: some versions of the article about the generous proposal portrayed it as being endorsed by Republican Party leaders; and some versions of the article about the meagre program described it as having Democratic support. The results showed that, “for both liberal and conservative participants, the effect of reference group information overrode that of policy content. If their party endorsed it, liberals supported even a harsh welfare program, and conservatives supported even a lavish one.”
In fact, the more engaged in the political process one is, the more this groupthink takes hold:
So instead of thinking and deciding the issues on the merits, political parties lead their members to think the party's stance on an issue is meritorious, rather than simply political gamesmanship. The media helps:In a 2006 paper, “It Feels Like We’re Thinking,” the political scientists Christopher Achen and Larry Bartels looked at a National Election Study, a poll supported by the National Science Foundation, from 1996. One of the questions asked whether “the size of the yearly budget deficit increased, decreased, or stayed about the same during Clinton’s time as President.” The correct answer is that it decreased, dramatically. Achen and Bartels categorize the respondents according to how politically informed they were. Among the least-informed respondents, Democrats and Republicans picked the wrong answer in roughly equal numbers. But among better-informed voters the story was different. Republicans who were in the fiftieth percentile gave the right answer more often than those in the ninety-fifth percentile. Bartels found a similar effect in a previous survey, in which well-informed Democrats were asked whether inflation had gone down during Ronald Reagan’s Presidency. It had, but many of those Democrats said that it hadn’t. The more information people had, it seemed, the better they were at arranging it to fit what they wanted to believe. As Bartels told me, “If I’m a Republican and an enthusiastic supporter of lower tax rates, it is uncomfortable to recognize that President Obama has reduced most Americans’ taxes—and I can find plenty of conservative information sources that deny or ignore the fact that he has.”
Equally fascinating in the article is how the constitutionality of Obamacare was a foregone conclusion several years ago, but the echo chamber of politics and the media gave the unconstitutional argument legitimacy to the point where a majority of Americans now believe Obamacare is unconstitutional....as we’re increasingly able to choose our information sources based on their tendency to back up whatever we already believe, we don’t even have to hear the arguments from the other side, much less give them serious consideration. Partisans who may not have strong opinions on the underlying issues thus get a clear signal on what their party wants them to think, along with reams of information on why they should think it.