The Houston Chronicle reported Sunday that, according to pollster John Zogby, Clinton appears to control South Texas, while Obama, leads in both Houston and Dallas. That would leave East Texas a vital territory in the Democratic fight for Texas' delegates.

Zogby said the polling numbers were simply too close to call the race for either candidate.

Saturday's tracking poll indicates the Illinois senator leads Clinton statewide with 46.7 percent support to the New York senator's 43.2 percent.

Zogby told the Chronicle while Obama is leading among male voters and in the black community, Clinton has countered with widespread support among Hispanics.

"It's very, very close. It's a four-point lead, nothing to take out a bank loan," Zogby said. "However, it's swinging back in Obama's favor. He's consolidated his group, young, African-Americans, men."