Republican J.D. Vance and Democrat Rep. Tim Ryan are locked in a heated contest in the Ohio senate race.

According to an Ohio Northern University poll taken in mid-October, Ryan leads Vance, 43% to 41%. The race has generated national attention as Democrats seek to hold on to the senate.

Ryan and Vance are battling for an open seat as Republican Sen. Rob Portman chose to not seek re-election.

Most polls had previously shown Vance ahead. According to polling data site Real Clear Politics, Vance was ahead of Ryan in 10 of 12 polls dating back to May. Most of the polls showed Vance's edge was at about 3 points.

Vance and Ryan recently squared off in a heated debate with both attempting to tie the other as too far from the center, with references to former President Donald Trump, conspiracy theorist Alex Jones, House Speaker Nancy Pelosi and Vermont Sen. Bernie Sanders.

Ryan has made strong efforts to move to the center, while Vance has been endorsed by Trump. A former chief of staff to Portman recently endorsed Ryan and the congressman has outperformed Vance among independents.

Ohio has leaned toward Republicans in recent elections, though Democrat Sen. Sherrod Brown remains very popular. Vance, who has never served as an elected official, may still have a big edge in a state that Trump won by about 8%.

"In our September poll, Vance had not solidified Republican support, coming off a hard-fought Republican primary that he had won with just 32% of the vote," said David Paleologos, director of the Suffolk University Political Research Center.

Ryan has a distinct advantage in campaign fundraising. He has raised $39 million compared to Vance's $10.5 million.