Many Kansas Republicans will have their eyes focused on Mississippi tonight, awaiting results of a primary runoff race between incumbent U.S. Sen. Thad Cochran and his Tea Party challenger Chris McDaniel.

Chief among those watching is Milton Wolf, the Tea Party-backed candidate who is trying to unseat U.S. Sen. Pat Roberts in the Aug. 5 primary in Kansas. In recent email news releases, Wolf has tried to equate Roberts and Cochran, who both have more than 40 years of tenure in Washington.

But state GOP officials are also paying attention. Clay Barker, executive director of the Kansas Republican Party, said the outcome of the Mississippi runoff could set the tone for the final five weeks of the primary campaign in Kansas.

After the Mississippi vote, Barker said, the next big contests for Tea Party challengers are the Aug. 5 primary in Kansas, and an Aug. 7 primary in Tennessee, where incumbent Sen. Lamar Alexander faces a Tea Party challenge from state Rep. Joe Carr. So the outcome of the Mississippi race could signal how much momentum the Tea Party movement still has, and how hard the next races on the calendar will be fought.

“It depends on who wins and how much resources they have left,” Barker said. “I think what we’ll see is probably more independent expenditures in Kansas.”

Tea Party-backed candidates have won only a few contested Senate primaries this year, notably in Montana and Nebraska, which both have open seats this year. But they failed to unseat long-term incumbents like Lindsay Graham in South Carolina, John Cornyn in Texas and Mitch McConnell in Kentucky.

Following the June 3 primary In Mississippi, McDaniel held a slim margin of about 1,400 votes, out of more than 300,000 cast. But neither candidate garnered more than 50 percent of the vote, setting up today’s runoff.

Cochran is widely viewed as an old guard, “establishment” Republican who built a career on his ability to bring back federal money for his home state. McDaniel has been endorsed by the Tea Party Express — the same group backing Wolf in Kansas — which promotes reducing the overall size of the federal government and halting what it calls “out-of-control spending” in Washington.

The most stunning upset of an incumbent Republican so far this year was U.S. House Majority Leader Eric Cantor’s loss to Dave Brat. Wolf, who routinely criticizes Roberts for spending more time in Virginia than in Kansas, quipped after that election that, “Eric Cantor isn’t the only incumbent from Virginia who is going to lose his primary this year.”

Roberts, however, said that he is not Eric Cantor and, “This is not going to happen in Kansas.”