WASHINGTON – Sen. Pat Toomey (R., Pa.) would lead either of his two leading Democratic challengers in a head-to-head match up by roughly equal margins, according to a Quinnipiac University poll released Thursday.

Toomey would lead Joe Sestak 47-39, and would lead Katie McGinty 47-38, the survey found. The poll did not test Toomey against Braddock Mayor John Fetterman, who is also running in the Democratic contest, nor did it compare how the three Democrats fare against one another in their April 26 primary.

The results are almost unchanged from a similar Quinnipiac's poll in August, when the race was just beginning.

The poll also found significantly superior approval ratings for Toomey than other recent polls have found, with 45 percent of voters seeing him favorably and 24 percent viewing him unfavorably.

A Franklin & Marshall poll last month found Toomey's numbers to be far worse, with a favorable-unfavorable rating of 30-35. Some Democrats have complained that Quinnipiac is using flawed methodology in Pennsylvania -- though such complaints have also become about as common as the polls themselves.

The Pennsylvania Senate race is among the most closely-watched in the country, and could determine control of the chamber.

The immediate question for Pennsylvania voters, though, centers on the Democratic primary.

Most polls have shown Sestak leading with McGinty in second, but a late burst of television spending, fueled by national Democrats, is geared at helping McGinty rally. The independent arm of Democrat's national Senate campaign operation is planning to run $1.1 million of TV ads as the race enters its final days, the Washington Post reported.

That is on top of a $1 million purchase by the Washington-based women's group EMILY's List, which is also backing McGinty.

National Democrats see her as the safer bet against Toomey, worrying that Sestak is too difficult to work with and that his unconventional tactics could cost them a winnable race. Sestak has said he is simply too independent minded for Washington leaders, and points to his close loss against Toomey in 2010, despite a GOP wave that year.

Fetterman has lagged in fund-raising, but insists he has grassroots support that can help him stage an upset.

The poll surveyed 1,737 Pennsylvania voters with a margin of error of 2.4 percentage points. It was conducted from March 30 - April 4.

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