Sen. Claire McCaskill of Missouri has officially begun her re-election campaign, the first and only Democrat so far in a contest that has attracted several Republicans.
Organizers of a proposed ballot initiative that would make it harder for Missouri legislators to overturn voter-approved laws say they are abandoning their efforts.
A national tea party group has endorsed former state Treasurer Sarah Steelman in Missouri's Republican U.S. Senate primary. But numerous Missouri tea party groups say they are not taking sides in the race.
