In America, we don't just pick presidents for who they are. We sometimes elect them because they're the opposite of the last guy.

This might be a form of psychological therapy, whereby we attempt to "work out" our past problems, but it seems to fulfill some sort of atavistic desire to exorcise demons.

In the wake of presidents like Johnson and Nixon and events like Vietnam and Watergate, a peanut farmer named Jimmy Carter became the beneficiary of this urge. After enduring eight years of George W. Bush's Texas swagger and malapropisms, we turned to a law professor named Barack Obama.

Each time, it was as if America said, "Let's do something entirely different. Let's spin the wheel."

So now, as scandals swirl around the Obama administration (IRS, James Rosen, Benghazi, AP, NSA — will it ever end?), it seems likely that the race to nominate a Republican to (hopefully) succeed Obama will be significantly shaped by this president's increasingly controversial tenure.

Just days after President Obama's second inaugural, I wrote that Sen. Marco Rubio probably had the best shot of being our next president. Considering the brewing backlash to Obama's scandals, I may have been wrong.

The problem with Rubio is that he was never the anti-Obama, but rather, "Our Obama." If conservatives were in the mood to "fight fire with fire" — to put up our young, smart, articulate, cosmopolitan conservative who says reasonable things — to be inspirational and talk about a new kind of hope and change and tell a personal story about the American Dream (our American Dream, this time) — then Rubio was perfectly cast.

But that strategy worked only so long as Obama was considered worthy of copying. And should these scandals continue, the American appetite might be for something altogether different.

Just as Obama was both a substantive and stylistic rejection of George W. Bush, so might Republicans look for someone completely different from Obama next time around. This is not to say that Rubio and Obama are identical. They're not. But it is to say that if you're looking for the opposite of Obama, you'd probably look somewhere else.

There are other reasons the Obama scandals hurt Rubio. Like every Republican worth his salt, Rubio can talk about the evils of big government. But that's not really his wheelhouse. He is better equipped to tap into Reagan's inspirational rhetoric — and George W. Bush's compassionate conservatism.

It is the rare politician who can play angry and friendly, hot and cold, and Rubio is not good at being angry. This is fine, except when the public is in an angry mood.

Since Obama's election, the conservative movement had already been heading in a more libertarian direction. That was true before the scandals. But the scandals reinforce this trend. This is a problem for Rubio.

Economist Arnold Kling has a new e-book out called The Three Languages of Politics. It is his contention that people who have differing ideologies are essentially speaking a different language. Progressives talk about the world as if it were a struggle between the oppressed and the oppressors. Conservatives view the world as a struggle between civilization and barbarism. And the libertarian worldview suggests it's all about freedom versus authoritarianism.

Rubio is good at speaking the conservative language. In fact, he's great at it. But these scandals really favor someone who is fluent in the libertarian language.

You might assume that this is a prime opening for Sen. Rand Paul, a libertarian-leaning conservative. And while there is little doubt that he has a chance, the truth is that the scandals might hurt both Rubio and Paul, for the simple fact that they are both unlucky enough to be U.S. senators serving in Washington, D.C.

In the decades prior to Watergate, the U.S. Senate was perhaps the stepping-stone to the presidency. This is not to say that men were elected to the presidency directly from the upper chamber (though that did happen for Kennedy), but Truman, Kennedy, Johnson, and Nixon had all served in the Senate.

After Watergate, something interesting happened. The next president to have served in the U.S. Senate — and let's be honest, he was there for a cup of coffee — was Barack Obama.

One could assume that this was merely a coincidence, or one could assume that it spoke to something larger — that the public decided to cast its lot with men who were removed from the trappings of power in Washington, D.C.

Who knows if history will repeat itself, but it is an argument for why Scott Walker, Chris Christie, Bobby Jindal, and Mike Pence (among others) should be taken very seriously.