At least one major establishment player is sitting out the expected runoff between Sen. Thad CochranThad CochranOvernight Finance: GOP offers measure to repeal arbitration rule | Feds fine Exxon M for Russian sanctions violations | Senate panel sticks with 2017 funding levels for budget | Trump tax nominee advances | Trump unveils first reg agenda Senate committee ignores Trump, House budgets in favor of 2017 funding levels Overnight Finance: CBO finds 22M more uninsured under Senate health bill | GOP agrees ObamaCare taxes must go | Supreme Court to look at Dodd-Frank whistleblower protections | More tax reform hearings | Green light for partial travel ban | MORE (R-Miss.) and primary challenger Chris McDaniel.

American Crossroads announced Wednesday, as the votes were still being counted in Mississippi, that it would not be wading into the fight.

“Other than Alaska, we have completed our work on Senate primaries this cycle and are now focused on general elections. With the Chamber [of Commerce], the [National Republican Senatorial Committee], and a local super PAC already backing Cochran, this is not our fight,” said Paul Lindsay, American Crossroads’s communications director.

That leaves Cochran lacking a major spender in what’s likely to be a fierce and expensive fight for the nomination, in contrast to the full-throated support national conservative groups have expressed for McDaniel.

Outside groups spent $8 million on the primary fight alone, with more than $5 million of that going to McDaniel.

Cochran heads into the runoff at a disadvantage, facing the challenge of maintaining enthusiasm around his candidacy and convincing persuadable voters and those who didn’t vote to go to the polls for him later this month. 

While both candidates need all the outside help they can get in the runoff — Cochran posted $681,000 cash on hand while McDaniel had $238,000 in mid-May, much of which has likely been depleted — Cochran may need it more, if national conservative groups again go all-in for the challenger.

And they indicated as much on Wednesday. FreedomWorks President Matt Kibbe said his group would “double down” for McDaniel in the runoff; Club for Growth President Chris Chocola said his group “will vigorously pursue this race to its conclusion."