Democratic presidential hopeful, Sen. Barack Obama, D-Ill., speaks during a town hall meeting Sunday, March 2, 2008, in Westerville, Ohio. (AP Photo/Rick Bowmer)
San Antonio (AP) Barack Obama says he's optimistic about today’s primaries in Texas, Ohio, Rhode Island and Vermont, but isn't counting Hillary Rodham Clinton out.
Obama told reporters in San Antonio Clinton is running a “tenacious campaign” and is “a hardworking candidate” with enormous resources.
He ended the day with a noisy late-night rally in Houston.