With every big name in national Tea Party politics lined up behind Ben Sasse in the Nebraska Republican Senate primary, a disinterested observer could be forgiven for assuming that Shane Osborn was some GOP Establishment today.

Except, that’s not the case. Osborn, a Navy veteran who was once captured and interrogated by the Chinese military for several days, served one term as the elected Nebraska treasurer, stepping down in 2011 rather than run for re-election. He has never lived in Washington aside from a 15-month assignment to the Navy Yard following his final deployment to Afghanistan.

Osborn moved home to Nebraska in May 2005 after being honorably discharged from the Navy. An early critic of the legislation that became Obamacare, he became a regular fixture at local Tea Party rallies protesting President Obama's health care overhaul. Later, as state treasurer, Osborn implemented a host of fiscal reforms.

With a resume like that, some political observers are perplexed by the conservative Establishment’s consensus endorsement of Sasse in the Senate primary.

Sasse, who still owns a home in Alexandria, Va., just outside Washington, served in former President George W. Bush's Health and Human Services Department. He lived in D.C. for a few years in the late 1990s, and from 2001 to 2009. But that Establishment pedigree hasn't deterred Tea Party groups like the Senate Conservatives Fund, and conservative icons like former Alaska Gov. Sarah Palin, from backing Sasse, who has run a small liberal arts college in eastern Nebraska since returning home.

Some Republicans monitoring the Senate primary suspect that Washington’s Tea Party community couldn’t resist playing in Nebraska. The deep-red state is sure to elect a Republican this fall, and with the seat being open, conservatives have an opportunity to influence the outcome for a relatively minimal investment. The Tea Party wants to expand its voting bloc in the Senate, and you can’t have a new ally in the chamber if you don’t help somebody win.

“I think it’s a cheap state and it was a good place to put taxidermy on the wall for a fairly low price,” a Republican strategist said.

Indeed, the May 13 contest to nominate a successor to retiring Republican Sen. Mike Johanns is the curious case of an intraparty battle that features two GOP contenders who give their supporters few reasons not to trust their promise to vote with Senate conservatives on key issues if elected. True, each candidate has a few flaws that ordinarily might give Tea Party activists pause, but they are similar and cancel each other out.

However, some Republicans argue that the conservative Establishment has made a deliberate endorsement in the race, one that explains much of the insurgent-Establishment divide that is roiling the GOP in a handful of 2014 Senate primaries. The national Tea Party groups aren’t concerned that Osborn will vote the wrong way in the Senate. Rather, they were attracted to the depth of Sasse’s ideological commitment to conservative principles and a political temperament that reflects their movement.

“Would you say there's a difference between [Texas GOP Sen.] Ted Cruz and Mike Johanns?” one GOP operative asked. “In terms of tactics and urgency, they approach being a senator very differently. It's not that they disagree on ideology but they have a different view of the world and how much trouble the country is in.”

The key question is whether any of this matters to Nebraska Republicans. These voters, not a bunch of conservative activists and professionals from out of state, will determine the winner of the primary. There are four candidates running, including wealthy banker Sid Dinsdale, who can afford to fund his own campaign if he chooses to. Osborn and Sasse are considered the favorites, in that order.

In 2012, in another open-seat GOP Nebraska Senate primary, Washington's conservative Establishment backed state Treasurer Don Stenberg over the early favorite, state Attorney General Jon Bruning. The conservative crowd invested heavily in Stenberg but came up short and a third candidate, now-Sen. Deb Fischer, won the primary.

The insurgent groups said that defeating Bruning constituted a victory, but state GOP insiders argued that Stenberg lost because primary voters were turned off by the negative ad campaign that was paid for by out-of-state interests. Because of that, political operatives monitoring the 2014 primary are watching to see how Sasse’s backers choose to operate in the Senate primary race.

A veteran of Nebraska politics who requested anonymity to speak candidly said the intra-GOP divide that exists in Washington is much less prevalent in Nebraska. Most state and local GOP officials, the Republican said, are equally involved in the party and Nebraska’s Tea Party community. Accordingly, the insider doesn’t expect Sasse’s outside support to carry as much weight among Nebraska Republicans as it might in other states.

“Their view of it is, you’ve got Sasse, Osborn and the other two guys, and they’re all going to vote 98 percent Republican conservative,” the Nebraskan said. “I think that’s part of the challenge of this primary, is how do you get the base fired up?”