Wichita ? U.S. Sen. Pat Roberts has touted endorsements from Kansas farm groups while campaigning for a fourth term, but the Republican incumbent likely will face questions about missed agriculture committee meetings Wednesday during his third and final debate with independent challenger Greg Orman.

Roberts was expected to continue attacking Orman as a liberal Democrat trying to hide positions on energy, immigration, health care and social issues that align with President Barack Obama and Senate Majority Leader Harry Reid.

The two will meet in a debate at the studio of Wichita station KSN for a high-stakes political showdown that will be broadcast statewide. The candidates have debated twice before since Democrat Chad Taylor withdrew from a race, leaving Roberts vulnerable in what had been a reliably red state. The contest has catapulted Kansas into the national spotlight amid a tight race with national implications for control of the Senate.

Republicans need a net gain of six seats to recapture a majority and has always counted on Roberts winning re-election. He’s seeking to unify the GOP behind him by highlighting his opposition to Obama and Reid. Orman is running as centrist and says he’ll caucus with whichever party has a clear majority.

But Orman has fresh ammunition going into the last debate in the wake of news stories which surfaced recently detailing the incumbent’s record of missed committee meetings in Washington.

The Topeka Capital-Journal reported this week that Roberts has attended barely one-third of all Senate Agriculture Committee meetings during the last 15 years.

Roberts serves on the committee responsible for farm, nutrition and forestry issues. He also is a member of Senate committees devoted to health, education, labor and finance topics.

According to documents from the U.S. Government Printing Office, Roberts showed up for only 71 of 201 agricultural committee sessions from 2000 to 2014, or 35.5 percent. He has also been under fire for missing a Sept. 16 hearing on the Ebola threat.

A Roberts campaign spokesman has called the senator a “tireless warrior for Kansas agriculture” and pointed Wednesday to endorsements from the Kansas Grain and Feed Association and the Kanas Agribusiness Retailers Association.