TOPEKA, Kan. (AP) — Republican Sen. Pat Roberts says a northeast Kansas businessman running against him isn’t truly an independent candidate but a liberal Democrat.

Roberts criticized independent candidate Greg Orman on Wednesday after a short, post-primary election rally at the Kansas Republican Party’s headquarters.

Orman is an Olathe businessman pitching himself to voters as a centrist. He said in an interview he expected such criticism from Roberts and called it a tired attack.

Roberts noted Orman’s 2007 contributions to Democrat Barack Obama’s presidential campaign, and his donations to Democratic congressional candidates. Also, Orman ran for U.S. Senate briefly as a Democrat in 2007 and early 2008.

But Orman said he’s given far more money to centrist causes.

Meanwhile, Roberts does face a Democrat in November — Shawnee County district attorney Chad Taylor.