Hillary Clinton and Barack Obama are neck and neck heading into a pivotal primary showdown Tuesday in Ohio and Texas, two delegate-rich states where Clinton held leads just weeks ago, according to two new polls released Sunday.
Clinton leads in Ohio by 47-43 percent. Obama leads in Texas by 46-45 percent. Those standings are both within the polls' 4 percentage point margin of error - meaning that either one could be ahead in each state. And nearly one in ten likely voters remains undecided in each state, more than enough to swing Tuesday's results in either direction.
The Texas poll was sponsored by McClatchy Newspapers, MSNBC and the Ft. Worth Star-Telegram. The Ohio poll was sponsored by the Cleveland Plain Dealer. Both surveys were executed by Mason-Dixon Polling and Research, Inc.
The surveys' slightly different results reflect growing anxiety about the economy and the different and diverse demographics in the two states.
Clinton, desperate for wins to stop Obama's momentum since he's run off 11 straight victories, has the edge among voters concerned about the economy, particularly in Ohio. She also has a 2-1 lead among Hispanics in Texas, while he has a 9-1 lead among African-Americans in both states.
How the two states vote could be critical to deciding who wins the Democratic presidential nomination. Should both states go for Obama, they would stretch his winning streak to 13 and put enormous pressure on Clinton to quit. Her own campaign has called them must-win states.
If Clinton were to pull off victories in both, that would break Obama's momentum, restore credibility to her campaign and could give her new energy heading into their next big showdown in Pennsylvania, which votes April 22.
"They're both close races," said Brad Coker of Mason-Dixon. "Hillary has a little better shot in Ohio. She still has a little lead there. Texas is a tossup."
In Ohio, the New York senator has lost the double-digit lead she had long enjoyed until a few weeks ago. She clings to a small lead thanks largely to the rise of the economy as an issue. Ohio voters who ranked the economy their top concern preferred Clinton over Obama by 51-35 percent.
Also, she benefits from the state's demographic makeup, Coker said.
"It's a little older electorate. White ethnic. More Catholic. There are fewer suburban liberals in Ohio," Coker said. "A lot of younger upscale latte liberals that Obama's been attracting elsewhere have fled Ohio."
She also has the advantage in Ohio among health-care voters, the number two issue in the state. The two are fighting fiercely over the issue; Obama charges that she would order all Americans to buy health insurance even if they couldn't afford it, and she insists that his proposed plan would leave 15 million people out.
Clinton leads in Ohio among women, voters over 50 years old, union members, whites and registered Democrats.
Obama, the Illinois senator, has the edge among men, voters under age 50, African-Americans and independents.
The North American Free Trade Agreement - a hot issue in a state where many people blame trade for lost manufacturing jobs and 59 percent say they oppose NAFTA - is a wash for the rival candidates. Ohio voters give neither an advantage on the issue.
In Texas, Clinton and Obama split the large minority votes. Hispanics made up 27 percent of the likely voters; African Americans 22 percent; and whites 48 percent.
Black Texas voters tilt overwhelmingly to Obama, 86-6 percent. He also holds leads among men (54-37 percent), people under 50 and independents.
Clinton has a 2-1 lead among Hispanic voters, as well as solid leads among whites (53-38 percent), women (51-40 percent), voters over 50 and Democrats.
"The Hispanic vote is saving her in Texas," Coker said.
She also leads among voters who say the economy is their top concern, 47-40 percent, a narrower margin than the 51-35 margin she won among economy voters in Ohio. As in Ohio, NAFTA is a draw, with neither candidate having an advantage.
The trend to watch for Tuesday in Texas is where voter turnout is heaviest.
Clinton likely will gain the upper hand if voter turnout soars in heavily Hispanic South Texas, including such cities as San Antonio and Brownsville, Coker said.
Obama benefits more if turnout is higher than usual in Dallas-Fort Worth and Houston, which would suggest that he's drawing votes from white suburban Republicans and independents, such as those who've voted for him in other states, Coker said.
"If Dallas and Houston vote the way they typically do in a primary, she can still pull it out," Coker said. "The higher the vote goes in Dallas or Houston, the better it is for Obama."
FULL POLL DATA
HOW WE POLL
The Mason-Dixon polls are snapshots of voter opinion at the time they were conducted. They are not a prediction of how people will vote on Election Day.
The Mason-Dixon poll of 625 likely Democratic primary voters in Ohio was conducted for the Cleveland Plain Dealer Feb. 27-29.
The Mason-Dixon poll of 625 likely Democratic primary voters in Texas was conducted Feb. 27-29 for McClatchy Newspapers, MSNBC, and the Ft. Worth Star-Telegram.
Those interviewed were selected by a random variation of telephone numbers from a cross section of telephone exchanges. That means anyone in the state with a phone line had the same odds of being called as anyone else, except for people who use cell phones only. Cell phone numbers are not in the exchanges.
The margin of error in both polls was plus or minus 4 percentage points. That means that 95 percent of the time, the correct numbers could be up to 4 percentage points above our poll's percentage point findings, or up to 4 percentage points below them. The other 5 percent of the time, the correct numbers could vary even more.
The sampling margin of error does not include other variables that could affect results, including the way questions are worded or the order in which they are asked.