(CNN) -- Sens. Hillary Clinton and Barack Obama are in a statistical dead heat in Texas, according to a poll released eight days before the state's crucial presidential primary.

In the CNN/Opinion Research Corp. survey released Monday, 50 percent of likely Democratic primary voters said Obama is their choice for the party's nominee, while 46 percent backed Clinton.

But taking into account the poll's sampling error of plus or minus 3.5 percentage points for Democratic respondents, the race is a virtual tie.

"The 2-point gain for Obama and the 4-point drop for Clinton are both within the poll's sampling error, so although the survey appears to indicate some movement toward Obama, we cannot say for certain that he has gained any ground since last week," said CNN polling director Keating Holland.