The Arizona Democrat is challenging the disqualification of 133 ballots.
Louisiana Dem says her GOP opponent voted to cut funding for schoolchildren to pay for it.
Warren will also visit the West Bank and Jordan in a move stoking 2016 speculation.
Finalists include Brooklyn, N.Y., Philadelphia and Columbus, Ohio.
Tea Party favorite drew applause from a crowd that included mega-donor Sheldon Adelson.
The potential '16 hopeful will keynote the University of South Carolina's winter graduation.
The Louisiana Democrat will take the field before Monday's Saints-Ravens game.
He retweeted at least a dozen tweets from random supporters urging him to run for president.
Hillary Clinton has a massive lead among Democrats.
Cameron Joseph 11/23/14 02:00 PM EST
Reid will try to maximize political benefits in advance of a tough reelection bid.