TOPEKA, Kan. (AP) — Establishment Republicans who'd been coy for months about the GOP primary for Kansas’ open Senate seat are increasingly putting their thumbs on the scale, hoping to push Rep. Roger Marshall to victory over polarizing conservative Kris Kobach.

A new GOP super-PAC this week launched what it promised will be a $3 million advertising campaign against Kobach with a spot that says he has ties to white supremacists, raising anew an issue that the former Kansas secretary of state has long battled as he advocated tough immigration policies. The political action committee's director previously worked for a Republican congressman and the state's GOP attorney general, and the group shares a media company with U.S. Senate Majority Leader Mitch McConnell's re-election campaign.

Marshall, the congressman for western Kansas, has racked up key business and anti-abortion endorsements. Even President Donald Trump stepped in last month, persuading the anti-tax, free-market Club for Growth to abandon a multi-million-dollar ad campaign against Marshall ahead of the Aug. 4 primary, a spokesman for the group confirmed.

Establishment Republicans have increasingly taken the extra step of rallying to Marshall's cause after months of publicly doubting Kobach's ability to win the November general election because of his loss in the 2018 governor's race. They're growing more vocal about describing Marshall as the best alternative for keeping the Kansas seat out of play in a potentially difficult fall for defending Republicans' Senate majority.

“You're seeing a lot of people starting to circle the wagons around Roger Marshall,” said Kelly Arnold, a former state GOP chairman. “They don't want to see the same mistakes happen again in Kansas."

Kobach, Marshall and Bob Hamilton, the founder of a Kansas City-area plumbing company, are running with eight other candidates in the most crowded GOP field since Kansas began holding Senate primaries more than 100 years ago. The previous record was nine candidates in 1978, and Nancy Landon Kassebaum emerged as the nominee with less than 31% of the vote before winning the general election. Kansas has no runoff elections.

Republicans are nervous partly because of the fundraising prowess of the presumed Democratic nominee, state Sen. Barbara Bollier, who reported Wednesday that she has collected more than $7 million in contributions through June — including a likely Kansas record of $3.7 million in the second quarter of the year alone — and entered July with $4 million in cash. Bollier also is a former lifelong Republican, having switched parties late in 2018, and is expected to appeal strongly to GOP moderates and independent voters, particularly in the state's most populous counties, which carried Kelly to victory in 2018. And Bollier is a retired anesthesiologist and is expected to highlight health care issues in the fall.

Many Republicans understand that Kobach “failed President Trump," by losing the governor's race despite Trump's endorsement, said Eric Pahls, Marshall's spokesman.

“Everyone knows Kris Kobach puts this seat in jeopardy, and that is not lost on the state party,” Pahls said.

Kobach is weaponizing Marshall's establishment support to help keep conservatives in his camp.

“McConnell World doesn't want a staunch conservative who can't be told to compromise,” Kobach said. “They want a pliable Republican who will take orders from McConnell.”

The first 30-second spot from Plains PAC, the new group attacking Kobach, notes that The Kansas City Star reported last year that an aide who’d been paid $500 by the Kobach campaign for field services had a history of making racist and anti-Semitic comments on a white nationalist website.

Kobach denounced the comments at the time, and spokeswoman Danedri Herbert called them “garbage" this week. She described the aide as an independent contractor, and he was fired by the campaign. Herbert said the super-PAC is recycling “old false attacks” previously leveled by Democrats.

But Plains PAC director C.J. Grover said the issue is one reason many Republicans have concluded “the man loses elections.”

“It’s not his policy positions,” Grover said. “It’s his toxic affiliations.”

Plains PAC plans to spend $2.1 million on television and radio ads around the state, according to Advertising Analytics, a company tracks political ads. The political action committee says it will advertise online as well.

It filed organization papers with the Federal Election Commission on July 1, listing an address in the Kansas City suburb of Overland Park. Grover formerly worked for former Rep. Kevin Yoder, who has endorsed Marshall, and state Attorney General Derek Schmidt.

A Baltimore-area company that bought television time for the PAC, Mentzer Media, also has done work for McConnell's campaign. The PAC holds its funds in a Washington-area bank that is one of 13 banks used by the National Republican Senatorial Committee.

That prompted Herbert to count the PAC among “McConnell’s establishment attack dogs,” through Grover said it is an independent group.

Meanwhile, the Kansas Republican Party’s leader has made moves that have Kobach and others seeing him as a Marshall backer even without a formal endorsement of the congressman.

“They're just protecting their guy,” Hamilton said. “It's very swampy.”

State GOP Chairman Mike Kuckelman canceled the last of four scheduled debates among GOP candidates before the Aug. 4 primary when Marshall’s rivals objected to the party’s plan to have a series of sessions with individual candidates rather than the usual group scrum. Kuckelman has suggested publicly that the Senate contest was “not the right race to start with" for the political neophyte Hamilton and worked earlier this spring to narrow the field.

“That was showing their hand, that they wanted everybody to be for Marshall,” said Tim Shallenburger, a former Kansas GOP chairman and state treasurer.

But Kuckelman said none of it adds up to a concerted push for Marshall. He said the party always anticipated that its last candidate event on July 15 might involve them talking issues rather than “throwing jabs.” He said any of the major GOP candidates are better alternative than Bollier.

“I don't care which of our candidates is the nominee,” he said.

Patrick Miller, a University of Kansas political scientist, said Kobach would likely benefit more than Marshall from a final head-to-head debate because it would give him another chance to draw distinctions for primary voters who tend to be “a few steps more conservative” than the GOP establishment.

And, Miller said, if Marshall were comfortably ahead, "There wouldn't be as much need for these kinds of things.”

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Associated Press writer Alan Fram in Washington also contributed.

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