LEAVENWORTH, Kan. (AP) — U.S. Sen. Pat Roberts gained a somewhat reluctant endorsement Thursday from his former Republican primary challenger, Milton Wolf, who urged Kansans to vote for the long-time incumbent despite their misgivings.

In a message posted on his campaign Facebook page, Wolf encouraged his supporters to set aside their differences with Roberts and support him in Tuesday’s elections in hopes that Republicans can take control of the chamber from Democrats and stand up to President Barack Obama.

Roberts has been making a similar argument as he campaigns against independent challenger Greg Orman.

“Whatever your opinion of Pat Roberts, his re-election to the United States Senate may be the deciding factor that dethrones (Senate Majority Leader) Harry Reid and elevates solid constitutional conservatives like (Sens.) Ted Cruz, Mike Lee and Rand Paul into positions of influence to save America from Barack Obama,” Wolf wrote.

Paul, Lee and Cruz all are favorites among tea party supporters who had backed Wolf in the August primary against Roberts. All three also have campaigned for Roberts in recent weeks. Lee, of Utah, on Thursday described Roberts as a “staunch advocate of constitutionally limited government.”

During the primary, Wolf argued that Roberts wasn’t a true conservative and accused him of becoming part of the Washington establishment, noting that Roberts’ official address in Kansas is merely a rented room in the home of a supporter. Roberts has served in the Senate and House since the 1980s and previously was a congressional aide.

If Roberts is re-elected, Wolf wrote on Facebook, “I will do everything in my power to hold his feet to the fire.”

An Orman campaign spokesman cited some of Wolf’s own comments from the primary as a reason why the endorsement should not be followed by voters.

“Like Milton Wolf, we believe that, ‘Roberts either can’t defend his record or is so arrogant that he no longer respects Kansas voters’ and ‘Pat Roberts left us a long time ago and now we need to bring him home — wherever that is — because nobody should spend 47 years in Washington,'” said Orman spokesman Mike Phillips.

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Associated Press writer John Hanna contributed to this report from Topeka.

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