Clinton is trailing Obama in the race for delegates who will decide the Democratic nominee.
Obama has accumulated 1,034 pledged Democratic National Convention delegates to Clinton's 955, according to an unofficial tally by thegreenpapers.com, a nonpartisan Web site that compiles election statistics. The count doesn't include the 796 so-called super delegates, Democratic Party officials and officeholders who aren't bound by primary or caucus results and can back whomever they choose.
A candidate needs at least 2,025 delegates to win the Democratic nomination at the party's convention.
Clinton picked up 26 more delegates yesterday when she was declared winner of the Feb. 5 New Mexico primary.
Along with Ohio, Texas also holds its primary March 4. The two states have a total of 334 pledged delegates available, and Clinton has campaigned in both over the past two days. Before Texas and Ohio vote, Democrats hold caucuses in Hawaii and a primary in Wisconsin on Feb. 19.