It's an article of faith among the Wingnuts that Barack Obama is the Black Jimmy Carter, and that Mitt Romney is - stop laughing - Ronald Reagan in 1980.
This is grasping at straws so thin you need a magnifying glass to even see them.
There have been four incumbent presidents kicked out of the Oval Office since 1897. William Howard Taft, Herbert Hoover, Jimmy Carter and George H.W. Bush. That's it.
Hoover stands alone as a unique situation, but the other three have some strong similarities.
First, all three had strong intra-party challenges for the nomination. Taft faced an internal revolt by the Progressives led by Teddy Roosevelt, his old mentor. Carter faced a challenge from his Left from Teddy Kennedy and Bush had a challenge from his right from Pat Buchanan.
Perhaps as a result of this "fractured base", all three races saw strong third party candidates. Roosevelt bolted the GOP and headed the Progressive party ticket and easily outpolled Taft in both the popular and electoral votes. John Anderson won 6.6% of the national vote and Reagan barely squeezed out a majority of the popular vote, winning 50.7% of the electorate. It was a landslide in the Electoral College, but Anderson polled over 5,700,000 votes. Bush, of course, saw Perot run in '92. Perot won 18.9% of the vote or over 19,700,000 votes.
Taft stole the progressive Republicans (back when there were such things), Anderson stole the moderate centrists and Perot stole the fiscal hawks.
In fact, you can even say the last time an incumbent PARTY was kicked out (1968, 1976, 2000) you also had special circumstances. In '68, George Wallace won 13.5%/9,900,000 votes. He carried four states in the deep South and probably tilted the upper South against Humphrey. Nixon won the popular vote by a mere 0.7%. In '76 you had Watergate, but even THAT vote was extremely close, with Carter winning by just 2.1% of the popular vote. And in 2000, you had the Nader effect in Florida and New Hampshire that effectively tipped the race to the loser of the popular vote. Even JFK in 1960 won by a razor thin margin.
Obama's election in 2008 was one of the few instances in recent memory (Eisenhower and FDR were the others) of a popular vote route of the incumbent party, much less a sitting president.
It just doesn't happen very often. In fact, Bush's narrow 2004 re-election was the closest margin for an incumbent since 1916.
People don't like to throw their Presidents out of office.
Or perhaps demographics are another way to look at it.
From 1932 until 1968, the Democrats won the White House unless they ran against Dwight Eisenhower. From 1968 until 1992, the Republicans won the White House unless they ran under the shadow of Watergate. From 1992 until 2008, the Democrats won the popular vote every time except 2004, when they had to face a sitting president.
Jon Chait has noted that this is a "must win" election for the GOP because demographically the dice are loaded against them for the next decade until they find a way to peel off minority voters or women. Put another way, the GOP will have trouble winning national elections until they stop being the GOP. But it's also "must win" because the economy is likely to pick up steam over the next two years. Whoever wins this November will get to preside over an economic expansion largely irrelevant to whichever party sits in the White House, just as Reagan benefited from the monetary expansion of '82-'84 that was entirely a product of the Federal Reserve.
The problem for Mitt Romney is that people historically don't like to throw out their President, demographics are turning against the GOP (see Graham, Lindsey) and no one likes Mitt Romney.