President Barack Obama and presumptive GOP presidential nominee Mitt Romney are virtually tied in the key swing state of Ohio, according to a poll released Thursday by Quinnipiac University.

Obama has an indistinguishable 45-44 edge, according to the poll. When voters are asked whether they would vote for an Obama-Biden ticket or a ticket with Romney and Sen. Rob Portman (R-Ohio), who many speculate will be Romney's vice presidential nominee, the two are still tied at 45-45.

In a poll on Feb. 15, the firm had Obama up 46-44 over Romney, and with the addition of vice presidents, he was up 47-43.

Other recent polls in Ohio have shown Obama with a slightly larger edge. The state has voted for the winner in every presidential election since 1960.

There remains a substantial gender gap in Ohio polling, with men voting 50-40 for Romney and women voting 49-38 for Obama.

Also on HuffPost: