Olathe ? A high-profile endorsement in hand in the unlikeliest of battleground states, veteran Republican Sen. Pat Roberts is seeking to bolster support in Kansas’ rural west, where he needs to win big to fend off independent challenger Greg Orman.

Roberts, who’s defending his seat against charges that he’s lost touch with Kansans, added another well-known name Wednesday to the list of Republicans backing him, former Gov. Bill Graves.

Orman, meanwhile, is staying on home turf in the more diverse Kansas City suburbs, talking in broad terms about a broken and dysfunctional Washington government, where Roberts has worked for more than 40 years.

The campaign geography signals where the candidates believe they need to shore up supporters before focusing on undecided voters. Polls have shown the race to be a dead heat, despite Kansas’ conservative leanings.

Republicans need to gain six seats to take control of the 100-seat chamber. They were not counting on having to defend Kansas, where only Republican senators have been elected since 1938.

Some in the GOP say they have been turned off by Roberts, whom they describe as drifting into the party’s ideological right wing during the summer’s hard-fought primary battle with tea party-backed Milton Wolf. The endorsement of Graves, a prominent moderate, was aimed at showing those divisions healing. Graves also recorded a statewide radio ad for Roberts.

Roberts’ team has brought in a weekly stream of high-profile advocates. Former presidential nominee Mitt Romney is scheduled Monday to campaign for Roberts, as Sen. John McCain and others have done.

“He is a reasonable man who understands how to solve problems for Kansans, often working on solutions out of the limelight or behind the scenes to deliver results,” Graves wrote in a letter endorsing Roberts.

Orman, 45, a wealthy Olathe businessman, is running as a centrist problem-solver beholden to neither party. He’s been backed by moderate Republican state legislators, and his campaign played down the Graves endorsement.

“The reality is that who endorses Roberts is not going to decide who wins or not,” said Orman adviser Dave Beattie. “The ceaseless political endorsements reinforce that Roberts is the insider and Orman is the outsider.”

Roberts looked vulnerable after the Aug. 5 primary campaign during which Wolf portrayed the 78-year-old senator as a creature of Washington, not Kansas. Since then he’s overhauled his campaign, at the behest of national GOP leaders, and has been traveling the state.

From Thursday through the weekend, Roberts is scheduled to make seven stops in western Kansas, where a substantial turnout in his favor will be needed to overcome the edge Orman is expected to have in Kansas’ urban and suburban counties.