Much has been made of Mitt Romney's cold reception among conservatives just a few months after being their standardbearer for the presidency. The usual reasons given are that Romney was too liberal on social issues, didn't run a good campaign, wasn't adequately charismatic, etc.

But Mitt Romney is only the latest in a long string of GOP presidents and presidential candidates to be shunned by their own party since Ronald Reagan. Let's look at them in sequence:

1992: George W. Bush loses to Bill Clinton. Between breaking the "no new taxes" pledge, losing fringe support to Ross Perot, and coming off as an out-of-touch Kennebunkport Yankee, Bush Senior was quickly shunned and forgotten by the conservative base.

1996: After a whopping defeat, Bob Dole was barely heard from again beyond making ads for erectile dysfunction. The GOPcouldn't even be bothered recently to pass a bill on behalf of the disabled in spite of his emotional presence and support.

2000-2008: Despite his lionization by the conservative establishment for years, it's important to remember that George W. Bush was dealt two major legislative defeats, largely by his own caucus. The first was his attempt to nominate Harriet Miers to the Supreme Court, and the second was immigration reform. After a narrow victory in 2004, Democrats rolled into control of Congress in 2006. After the financial crisis and bailout in 2008, Bush Junior was so unpopular that he had to stay well out of the public limelight to give John McCain a chance.

2008: Speaking of John McCain, he was so ill-liked by the Republican establishment even prior to his defeat that he felt the need to rally his base by nominating the famously ignorant Wasilla Wonder as his vice-presidential nominee.

2012: Mitt Romney. No comment necessary.

Nor have the vice-presidential picks fared much better: of Dan Quayle, Jack Kemp, Dick Cheney and Sarah Palin, and Paul Ryan, only the last three have much respect among the GOP base. But Palin and Cheney are absolutely toxic to those who aren't hardcore conservatives, and Paul Ryan is well on his way there.

Democrats, by contrast, have no such problem. Progressives have been upset with Bill Clinton, Al Gore, John Kerry and Barack Obama for various reasons. But they have remained popular not only with the majority of the Democratic base, but also among the general public. Both Bill and Hillary Clinton are rockstars in the party with high public approval ratings. Al Gore has become a respected leader on climate change and sympathetic figure given the way the 2000 election was snatched from him. And Barack Obama is still Barack Obama. Of the Vice Presidents and VP candidates, only Joe Lieberman has become toxic for his politics (Edwards would still be popular but for his personal indiscretions)–and that because he has moved so far to the right.

What does all of this mean? It suggests something rather powerful.It suggests that Republican policies are deeply unpopular and ineffective, but that the Republican base refuses to believe or acknowledge that to be true.

Republican Presidential candidates have lost the popular vote in five of the last six elections. Their base has no choice but to blithely interpret those results as the product of inadequate conservatism. Yet those presidential candidates have usually chosen more conservative vice-presidential candidates to help rally the base–and those vice-presidential picks are even moreallergenic to the public than the presidential nominees.

Meanwhile, the only Republican to win the popular vote in the last six election cycles was George W. Bush, a presidential failure so monumental that Republicans have cleansed their memories of his very existence.

Democratic presidents and candidates have no such problems. Bill Clinton was a successful president. Al Gore's warnings about Social Security lockboxes and climate change have been proven right. John Kerry's warnings about Republican financial and foreign policy have been proven right. And despite our numerous misgivings as progressives, Barack Obama remains a largely popular president navigating the worst economy since the Great Depression.

It should come as no surprise, then, that Mitt Romney is the latest victim of the Right's capricious relationship to its standardbearers. The problem isn't their candidates. It's their ideas. But the Right is all too happy to blame the candidates when their ideas fail the test of reality and public opinion.