The frontrunners for the 2016 GOP presidential nomination all get similar levels of support in a new poll from Quinnipiac University.

The poll shows five Republicans in double digits, but none of them reaching 20 percent.

The top five are:

Sen. Marco Rubio (Fla.) - 19 percent

Rep. Paul Ryan (Wis.) - 17 percent

Sen. Rand Paul (Ky.) - 15 percent

New Jersey Gov. Chris Christie - 14 percent

Former Florida governor Jeb Bush - 10 percent

A trio of governors -- Louisiana's Bobby Jindal, Virginia's Robert F. McDonnell and Wisconsin's Scott Walker -- bring up the rear, with none of them getting more than 3 percent.

Interestingly, despite the top three contenders coming from Congress, Republicans and Republican-leaning voters said by a 59-23 margin that they'd prefer to nominate a governor rather than a senator.

Among all voters, Republicans in Congress get just a 19 percent approval rating, with 71 percent disapproving. And on the generic ballot (asking people whether they would vote for a generic Democrat or a generic Republican), Democrats have opened an eight-point lead -- their widest advantage since it was also eight points in Nov. 2011.

Update: A new Marist-McClatchy poll also tests some general election matchups, with Hillary Clinton and Vice President Biden leading all Republicans -- except Christie.