Former Alaska Gov. Sarah Palin lent her Tea Party credibility to former Oklahoma House Speaker T.W. Shannon, endorsing his effort to replace retiring Sen. Tom Coburn as the next Republican senator from the state.

"T.W.'s opponent has the backing of Beltway insiders, but T.W. has the passion and experience We the People need in Washington," Palin wrote in a Facebook post, referring to Rep. James Lankford, R-Okla. "As the former Speaker he can stand proud on his record of fighting for conservative legislation that directly benefited the lives of Oklahomans by lowering taxes, cutting government waste, and breaking the cycle of poverty by encouraging entrepreneurial self-reliance as the proven path to prosperity."

Lankford came to office in 2010, in part because of the strength of his grassroots support among Christians in his district. But some conservatives say he has gone native in Washington. Still, it's not clear that this campaign will turn into the same insider/outsider fight that has unfolded in other Republican primaries over the last few years.

Sen. James Inhofe, R-Okla., predicted that Shannon wouldn't make it that kind of race. "I know Shannon well enough to know that it's not going to be that way," he told the Washington Examiner on Tuesday.

The Senate Conservatives Fund, one of the most prominent conservative campaign groups, wanted Rep. Jim Bridenstine, R-Okla., to run even though Shannon was an option. Since Bridenstine declined to run, SCF has stayed on the sidelines.

Palin's endorsement comes on the same day the Washington Post reports that an internal Lankford poll taken last month shows him leading Shannon by 30 points. That poll showed Shannon with just 31 percent name recognition (26 percent favorable, five percent unfavorable), so Palin's endorsement could be an important factor in elevating his credibility with conservative voters.

We'll find out soon enough.