Kansas City, Kan. — The big-name Republicans parading through Kansas tout Sen. Pat Roberts as the key to breaking Democratic control of the chamber, but seldom do they mention his record over 34 years in Congress.

On Friday, it was New Jersey Gov. Chris Christie who — like other GOP stars before him such as Texas Sen. Ted Cruz, Kentucky Sen. Rand Paul and former Florida Gov. Jeb Bush — provided a pitch for the three-term incumbent without much elaboration.

“If I were a Kansan, I would be voting for Pat Roberts,” Christie told reporters during a stop near Kansas City.

Charlie Black, a veteran Republican presidential strategist, calls such appearances by celebrity politicians a “long tradition designed to demonstrate party loyalty,” sometimes more beneficial to the visitors — many of whom have national ambitions.

At first, Christie, chairman of the Republican Governors Association, didn’t even mention Roberts during his brief remarks outside a chartered bus he and several Kansas Republican officials such as Gov. Sam Brownback were traveling this week. Later, he acknowledged his main mission on the trip was to tout Brownback.

And Paul on Tuesday gave Kansans this rationale for voting for Roberts: “You’re a Republican state, for goodness sakes,” he said in Wichita.

Wisconsin Rep. Paul Ryan, the GOP vice presidential nominee in 2012, gave among the more specific endorsements, touting “Roberts’ seniority and stature and clout and hard work ethic.” Ryan also described the dry-witted Roberts as among “the funniest people I’ve ever met.”

But Roberts, who fought off a tea party challenge in the August primary, hasn’t discussed his record often while campaigning. Some conservatives are angry that he backed farm bills viewed by fiscal hawks as corporate giveaways. He now is locked in a neck-and-neck struggle with Greg Orman, a 45-year-old wealthy Kansas City-area businessman, and is hoping the attention from well-known party members will get him across the line on Tuesday.