Every poll conducted over the last two years makes one thing crystal clear: Voters are sick of the status quo in Washington and want outsiders to shake things up.

( Former Massachusetts governor Mitt Romney and former House Speaker Newt Gingrich are the favorites for the Republican presidential nomination.)

Romney ran unsuccessfully for the U.S. Senate in 1994, spent four years as governor of Massachusetts from 2002 and 2006 and has been running for president, essentially, since then. Gingrich has been in and out of elected office for three decades and ascended to the top of the U.S. House in 1994.

So, what gives?

“The truth is we rarely elect genuine outsiders,” said Vin Weber, a former Member of Congress and supporter of Romney’s presidential bid. “We elect people like [Bill] Clinton and [Ronald] Reagan who spend years cultivating insiders while preserving an outsider image.”

A quick look back at recent electoral history proves Weber’s point. The closest thing to a genuine outsider winning a party’s presidential nomination was then Illinois Sen. Barack Obama in 2008; Obama wasn’t the pick of the party establishment and had only spent two years in the Senate when he announced his bid.

But, Obama is very much the exception to the rule. Republicans nominated Arizona Sen. John McCain, who had spent three decades in Washington, to face off against Obama. (To Weber’s point,McCain, despite being a pillar of the Washington establishment was able to win the Republican primary largely by casting himself as a maverick.)

In 2004, Democrats flirted with an outsider — former Vermont Gov. Howard Dean — before settling for an insider in Massachusetts Sen. John Kerry. In 2000, Republicans went with George W. Bush, a man so inside that his own father had been president just eight years earlier.

Go as far back as 1996 and the “insider over outsider” trend is still apparent. Republicans nominated perhaps the biggest insider of them all — Senate Majority Leader Bob Dole — to challenge Clinton for a second term.

That the insider almost always emerges as the party’s presidential nominee is tough to dispute. The “why” of that fact is a tougher question to answer.

The simple answer is — as almost always — likely the right one. And the simplest answer is that running for president is a very difficult thing to do. Insiders tend to have spent years priming the pump for these sorts of national bids — readying themselves for the national glare, building out their organizations nationally and in early states, preparing a policy platform and recruiting surrogates to their cause.

Outsider candidates, by their very nature, don’t typically do that sort of leg work in advance and, as a result, are forced to try to do it all on the fly. It almost never works.

“Experience matters,” said Ken Duberstein, who served as chief of staff to then President Ronald Reagan. “You have to know you’re way around to change and challenge ‘the system.’”

Take Herman Cain’s now-suspended campaign. Cain’s rise was sparked by his unconventional approach to politics; he touted that he was the only non-politician in the field at nearly every public forum at which he appeared.

But, Cain’s outsider status also sewed the seeds of his campaign’s implosion. He was unable to offer a coherent and consistent pushback against the allegations of sexual harassment and infidelity that sidetracked his campaign. He lacked effective surrogates to defend him. He didn’t have any real on-the-ground organization in early-voting states that he could fall back on to reassure supporters that he was in the race to stay.

Going forward then, the fight for the Republican nomination is not between an outsider and an insider but rather between two insiders — each of whom is doing their best to paint themselves as the more outsider-y. (Probably not a word but you know what we mean.)

And both men are working hard at it.

“I have spent most of my life outside of politics, dealing with real problems in the real economy,” Romney said in August. “Career politicians got us into this mess, and they simply don’t know how to get us out.”

Romney also recently described Gingrich as a “lifelong politician”, adding: “He spent his last 30 or 40 years in Washington. I spent my career in the private sector.”

Gingrich, for his part, has insisted that “I’m not a Washington figure” but rather “an American whose ties are across the country and is interested in how you change Washington, not how you make Washington happy.”

The reality is that neither Romney nor Gingrich is a natural fit as an outsider to the political process. Which is exactly why they find themselves as the last two men standing in the primary fight.

“Over time, politicians tend to make the best politicians,” said longtime Republican strategist Ed Rogers. “The best politicians are rising to the top.”

Rachel Weiner contributed to this report.

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