McCaskill planned stops Monday in Columbia, Springfield, Kansas City and St. Louis County to encourage volunteers who have been canvassing neighborhoods. Akin planned five stops at Republican offices in the St. Louis area as part of his final get-out-the-vote effort.

Democratic Gov. Jay Nixon and Republican challenger Dave Spence also had a packed schedule of statewide campaign events Monday.

Polls will be open from 6 a.m. to 7 p.m. Tuesday.

Election officials have forecast that 72 percent of registered voters will turn out to cast ballots.