The colleagues of Kansas Republican Reps. Jerry Moran and Todd Tiahrt are beginning to take sides in their 2010 Senate primary.

Both lawmakers are running to succeed retiring Sen. Sam Brownback (R), setting up a Member-versus-Member primary that could divide their Congressional colleagues as well as Republicans in the Sunflower State. Brownback is stepping down to run for governor in 2010.

Kansas Gov. Kathleen Sebelius, who had been viewed as the only Democratic candidate who could compete for the Senate seat, is expected to be confirmed as Health and Human Services secretary when Congress returns from the Easter recess.

With the winner of the GOP primary now clearly favored to win the Senate race, the stakes are higher, and more Members are beginning to take sides.

Several Republican Senators hosted a Feb. 24 fundraiser at the National Republican Senatorial Committee for Moran’s bid — but not all of them are endorsing the 1st district Republican.

Meanwhile, Tiahrt is getting a high-profile assist from former Speaker Dennis Hastert (R-Ill.), who is hosting a luncheon fundraiser for Tiahrt in Chicago later this month, according to a copy of the invitation obtained by Roll Call. At $1,000 per ticket, there’s no doubt Hastert supports Tiahrt in the Senate contest.

But neither Moran nor Tiahrt seems anxious to name their current supporters in the House because they are mindful of putting their colleagues on the spot.

“I’ve consciously made the decision that I’m not going to try and put anybody in a particularly difficult position,— Moran said. “Two House Members potentially running for the same Senate seat is a very awkward thing, so I’ve twisted no arms in the House.—

A spokesman for the Tiahrt campaign, Sam Sackett, declined to name any of his Congressional endorsements.

“Congressman Tiahrt has a distinguished record that has earned him deep respect among his colleagues in the House and the Senate,— Sackett said. “The campaign is not releasing its list of Congressional endorsements at this time. Congressman Tiahrt instead is working hard to earn the endorsements of Kansans across the state and is pleased with the positive reception he has received.—

But the other chamber is a different story.

“There’s a cadre of friends and supporters in the Senate who are interested in having me join them,— Moran said.

GOP Sens. Tom Coburn (Okla.), Richard Burr (N.C.), Jim DeMint (S.C.), John Ensign (Nev.), Mike Johanns (Neb.) and John Thune (S.D.) headlined the Moran event at the NRSC, according to a list obtained by Roll Call.

Coburn announced last month that he was supporting Moran’s bid, and a source close to Johanns confirmed the Nebraska Republican is also supporting Moran. In response to an inquiry about the Kansas Senate race, Thune had praise for both Kansas Republicans — but said he’s backing Moran.

“Todd is a good friend, and he has family in South Dakota whose support I have enjoyed over the years,— Thune said. “However, Jerry has also been a very good friend for many years, and he asked for my support last year and I agreed to support him.—

According to Burr’s head campaign consultant, Paul Schumaker, Burr has not issued an official endorsement of Moran — nor has he been asked to do so. Schumaker added that Burr inherently supports Moran by fundraising for him, but would not comment on whether he would also do a fundraiser for Tiahrt.

“If you attend an event and it’s raising money to support a campaign, that’s what it’s for,— Schumaker said.

But others on the invitation said they were merely helping Moran raise money and have not picked sides in the contest. A DeMint aide said the Senator has not endorsed in the Kansas primary but just signed on to fundraise for Moran at that specific event.

Ensign spokeswoman Rebecca Fisher said the former NRSC chairman “thinks highly of both candidates— and has not picked a side yet. Ensign hosted a fundraiser for Tiahrt on March 3 at the NRSC — less than two weeks after he lent his name to the event for Moran.

In some cases, Moran’s support hits close to home — literally. When he’s in Washington, D.C., Moran shares a residence with Thune and Coburn, plus several other Republican and Democratic Members. Moran declined to name his roommates in an interview, saying he did not want to put any of them on the spot.

At least one Tiahrt supporter took issue with Coburn’s public endorsement of his roommate.

“I’m sure Mrs. Tiahrt supports Tiahrt, too,— quipped a longtime Kansas Republican who supports the 4th district Congressman.

There is no indication from either campaign about whether the two Members might seek to publicize their support from their House colleagues as the primary date draws nearer.

Rep. Tom Cole (R-Okla.) said he has not endorsed either of his Kansas neighbors, nor does he plan to take sides in the battle.

“No, obviously they’re both very good friends,— Cole said. “I don’t think my opinion would be particularly worth a great deal in Kansas, and they’re just both terrific guys, really excellent people.—

As for Hastert’s event for Tiahrt, there could be some history behind it.

The Associated Press reported in 2004 that Hastert anonymously criticized Moran in his book, “Speaker,— for allegedly switching his vote on the controversial Medicare prescription drug bill — a measure that barely passed the House.

“One Prairie State Member, a fourth-term representative from a solidly Republican district, voted no, then ran and hid,— Hastert reportedly penned in his book. “I sent people to find him. They couldn’t.—

Moran told the AP reporter at the time that Hastert’s words make “no sense to me,— adding that he was consistent on the issue from the beginning and that he didn’t think the Illinois Republican was referring to him in the book.