The problem with the OP’s question is that it doesn’t really specify what constitutes a conservative Republican. One issue that the Republican party, and conservatives more generally, have faced in the post-WWII era is reconciling traditionalist conservatism, which tends to focus heavily on religion and the moral priorities that come with evangelical Christianity, and libertarian conservatism, which is more interested in free market economics and a definition of freedom that involves minimalist government intervention.
There have been, and are, plenty of overlaps among these groups, and there are also conservatives with more specific priorities that draw a little bit from each, but a fundamental problem of conservatism is the difficulty of balancing the different priorities among the fairly broad group of Americans who consider themselves to be conservatives and/or Republicans. (Liberals often face similar problems, but that’s not who this thread is about.)
The tension between the traditionalists and the libertarians was pretty pronounced for much of the 1950s and 1960s, although William F. Buckley managed to bring the two groups together in some important ways, at least with respect to conservative intellectuals. In national politics, Ronald Reagan also managed to get both of these groups on board, although anyone who followed Reagan’s politics knows that, while he made some big promises to the moral majority, and talked a lot about God in his speeches, he didn’t actually do very much during the eight years of his presidency to advance the evangelical cause. Plenty of religious conservatives were really disappointed with Reagan.
One of the things that got libertarian and traditionalist conservatives on board together in the post-war era was hostility to communism. The broader rhetoric of opposition to taxation, and to liberal social programs like welfare also often unites them. Agreement about foreign policy during the Cold War was, in many ways, a bit easier than it is today. Tensions over foreign policy today also make conservative unanimity difficult because the enemy is seen by many as not just an ideology, but an actual religion. Conservatives who advocate a measured and thoughtful approach to terrorism sometimes find themselves being shouted down by rank and unsophisticated anti-Islamic rhetoric, and this sort of thing is helping to drive Trump’s campaign among a subset of conservatives.
But there are also broader differences to consider. For example, libertarian conservatives aren’t generally interested in regulating morality. They don’t give a flying fuck about preventing gay marriage, many of them are happy with the legalization or decriminalization of weed, and they also didn’t jump on the anti-feminist bandwagon in the same way that traditionalists did. Many of them are also supporters of the right to abortion, something that has enraged traditionalists. The individualistic idea of freedom favored by libertarian types often runs in direct conflict with the traditionalist idea of regulating society’s morality based on fundamentalist Christianity.
There are also conflicts over things like immigration. While the immigration debate is often portrayed as a liberal versus conservative thing, it’s more complicated than that. While many conservatives are strongly opposed to open immigration and amnesty for illegal immigrants, some of the biggest proponents of more open immigration regulations over the course of the past hundred years have been large employers, including big agribusiness, who often see themselves as conservatives but who also want to benefit their own bottom line by using labor competition to drive down wages. And these conservatives have often benefited from government regulation, in areas like the Bracero program (1942-64), which basically gave them a large imported labor pool to help keep down the wages of domestic agricultural labor. (On the other side of the political fence, one of the biggest opponents of open immigration in American history has been the organized labor movement (often associated with liberal politics). Labor unions, on many occasions in the 20th century, used both economic arguments about job competition, as well as rather unsavory nativist and racist rhetoric, in order to oppose immigration.)
Even within these groups, there are often inconsistencies. The libertarian trend in American conservatism, which grew into a national movement after Barry Goldwater’s 1964 Presidential bid, based much of its politics on the idea of reducing the size of government. But much of Goldwater’s small-government support came from the Sun Belt in the American southwest, where many of the same people who railed against government spending (or, at least, spending on liberal programs) also benefited directly from jobs in aerospace and defense contracting, which received massive amounts of taxpayers’ money during the Cold War. It’s always amusing seeing someone who spent his whole life making six-figure salaries for a defense contractor complaining about the size of government.
If there’s something that unites the disparate strands of American conservatism better than anything else, it has been that, no matter what their disagreements, they still see liberals (and, by extension, the Democratic Party) as a bigger enemy. The problem they face, in the period of declining government programs since Reagan’s election, is that Democratic presidential candidates have moved to the right, especially on issues of welfare programs, and have brought with them many moderate Republicans who are not invested in the traditionalists’ culture wars. Clinton got broad support by promising to end welfare as we know it, and even Obama (despite Obamacare, and all the bullshit rhetoric about his alleged socialism) represents a continuation of the movement away from New Deal-style politics that began in the Democratic Party during the 1970s and 1980s.
And all of this also doesn’t consider some of the more recent splits in the party, which in some cases seem to be less about specific ideology than about trying to wrest control of Congress away from party insiders, who often seem more interested in consolidating their power using rules of seniority and procedure than in actually making policy. This reflects, in some measure, the “true conservative” versus “establishment conservative” rhetoric that DSeid talks about. And he rightly notes that it’s not just about who supports you in American politics; it’s about who actually gets off their ass and votes.
I’d be interested to see what a Bernie Sanders presidential candidacy would actually do to the splintering in the Republican Party. My hunch is that it would drive the moderate, libertarian-leaning Republicans back into the arms of the traditionalists, uniting around a candidate that promised to keep cutting welfare programs and taxes, and who also made some promises (genuine or otherwise) about reversing America’s so-called moral decline.
There is the possibility that increasing economic inequality might drive poorer conservatives towards a socialist candidate. There has been, in American history, no necessary contradiction between traditionalist moral values and a more socialist political and economic view of the world. States like Alabama and Minnesota and Kansas and Wisconsin and Iowa and Nebraska have all, in the past, embraced movements that were strongly rooted in Christian morality, but that also called for bigger government to protect the people from political corruption and the inequities of monopoly capitalism. The Grange movement, the Farmers’ Alliances, the Populists, and the Progressives all had solid bases in rural, moral-conservative America. Socialist Huey Long came from Louisiana.
That was a long time ago, and i’m not arguing that this will actually happen, especially in the near future. I think it would take a lot for moral conservatives to embrace a leftist political and economic movement. But while big shifts in the political landscape take time, they can and do happen. There were plenty of liberal Americans in the mid-1960s who, celebrating LBJ’s Civil Rights Act and the Great Society and the War on Poverty and Medicare/Medicaid, probably would have laughed in your face if you told them that someone like Ronald Reagan would be elected to the presidency within 15 years.