SAN ANTONIO, Texas--White House hopefuls Hillary Clinton and Barack Obama are deadlocked in Texas and Ohio ahead of crunch Democratic nomination tests in both states, a new poll showed Saturday.

Clinton regained lost ground against Obama in Texas while he continued to creep up in Ohio before Tuesday's votes, which could sink or save the former first lady's campaign, according to the Reuters/C-Span/Houston Chronicle two-day tracking poll.

Obama was leading Clinton 45 percent to 43 percent in Texas, a virtual tie given the poll's plus or minus 3.8-point margin of error, according to the telephone survey of 708 likely Democratic voters taken between Wednesday and Friday.

A previous tracking poll also carried out by the Zogby Institute and released Friday showed Obama leading Clinton 48 to 42 percent in Texas.

In Ohio, the Democratic contenders were tied at 45 percent, according to Saturday's poll. It was conducted among 701 likely Democratic voters and also has a 3.8-point margin of error.

But a Fox News/Opinion Dynamics poll released Friday showed Clinton with a comfortable 46 to 38 percent lead in Ohio. The poll among 600 Democrats, taken between Tuesday and Thursday, has a four-point margin of error.

In Texas, Obama led 48 to 45 percent, according to the Fox News/Opinion Dynamics survey.