WASHINGTON (Reuters) - Democratic presidential hopeful Hillary Clinton has double-digit leads over Barack Obama in Ohio and Pennsylvania, both crucial states in upcoming primaries, according to Quinnipiac University poll released on Thursday.

Clinton, a New York senator, has lost eight straight nominating contests to Illinois Sen. Obama, but leads him 55 percent to 34 percent among likely Democratic primary voters in Ohio, the poll found.

Among Ohio Democrats, women back Clinton, 56 percent to 30 percent for Obama, while men back Clinton 52 percent to 42 percent, the poll found.

White Democrats favor Clinton 64 percent to 28 percent, while Obama leads 64 to 17 percent among black voters, according to the survey.

“Ohio is as good a demographic fit for Sen. Clinton as she will find,” Peter Brown, an Quinnipiac University Polling Institute official, said in a statement.

“It has blue-collar America with a smaller percentage of both Democrats with college educations and African-American than in many other states where Sen. Obama has carried the day.”

Ohio, Rhode Island, Texas and Vermont hold nominating contests on March 4. Pennsylvania voters will select presidential nominees in a primary election on April 22.

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The survey found that among likely Democratic primary voters in Pennsylvania, Clinton leads Obama 52 percent to 36 percent.

In a general election matchup with Republican front-runner John McCain, Ohio voters give the Arizona senator 44 percent support to 43 percent for Clinton and 40 percent for Obama.

In Pennsylvania, Clinton leads McCain 46 percent to 40 percent in the general election, Obama has 42 percent to McCain’s 41 percent, the poll said.

The Quinnipiac University poll was taken February 6 through 12, after the “Super Tuesday” contests in which McCain all but wrapped up the Republican nomination with coast-to-coast primary victories.

The Ohio poll of 1,748 voters has a margin of error of plus or minus 2.3 percent, including 564 Democratic likely voters with a margin of error of plus or minus 4.1 percent.

The Pennsylvania poll of 1,419 voters has a margin of error plus or minus 2.6 percent, including 577 Democratic likely voters, with a margin of error of plus or minus 4.1 percent.