(CNN) - In a new survey of potential 2016 presidential candidates, 52% of registered voters say they have a favorable opinion of former Secretary of State Hillary Clinton, down from 61% who said the same thing in February.
But the Quinnipiac University poll shows Clinton would be the favorite in hypothetical matchups against Republican Sen. Rand Paul of Kentucky and former Florida Gov. Jeb Bush.
Clinton finished out her term in early February with high marks in public polls. But as she has largely stepped out of the limelight and as Republicans have ramped up efforts to pin the Obama administration over the Benghazi attack, the new survey released Friday indicates her favorable rating has dropped.
Among Democrats, she's still highly popular, with 91% saying they view her in a favorable light, while 46% of independents and only 18% of Republicans feel the same way. Broken down by gender, 59% of women say they have a positive opinion of her, while less than half of men-44%–agree.
"The drop in her favorability is substantial among men, Republicans and independent voters. One reason for her drop may be that 48 percent of voters blame her either a little or a lot for the death of the American ambassador in Benghazi," said Peter A. Brown, assistant director of the Quinnipiac University Polling Institute.
Vice President Joe Biden's rating has also decreased over the same time period, from 45% to 31%, among registered voters.
On the Republican side, Sen. Paul has already been traveling to early primary states as he expresses interest in a 2016 presidential campaign. In a matchup against Clinton, however, the Kentucky senator falls behind, 41% to Clinton's 49%.
Bush, who has not been as active in stoking 2016 speculation, also falls behind Clinton in the poll, 40% to 48%.
If Biden were in the picture, however, the tables would turn. Paul fares better in a matchup against Biden, 43% to 39%, as does Bush, 44% to Biden's 38%.
"If Ms. Clinton chooses not to run in 2016, the potential Democratic field could include a somewhat unpopular vice president and a number of new faces who are unknown to the vast majority of Americans," said Brown. "The potential Republican candidates include many unknowns also," Brown added. "Some of them, however, lead the incumbent vice president and outscore him when it comes to overall voter favorability."
For the survey, Quinnipiac surveyed 1,419 registered voters by telephone from May 22 – 28, with a sampling error of plus or minus 2.6 percentage points.