TOPEKA, Kan. (AP) — U.S. Sen. Pat Roberts and Kansas Gov. Sam Brownback are hitching their re-election campaigns together in a cross-state tour.

Roberts and Brownback were to set out Wednesday from Topeka on a four-day bus tour that includes stops in at least 19 Kansas cities and towns.

Both of the Republican incumbents are locked in close campaigns. Roberts faces a challenge from independent candidate Greg Orman, a Kansas City area businessman. Brownback is being challenged by Democrat Paul Davis, the Kansas House minority leader.

Election Day is next Tuesday.