After months of heavy campaigning in a crucial state, Republican Sen. Pat Toomey and his Democratic challenger Katie McGinty will face off Monday in their first debate, set to air at 7 p.m.

Sharp differences in policy divide the candidates: national security, taxes, health care, Wall Street regulations and gun control. No doubt both candidates will leverage their stance on these topics to eke out a win.

As of Monday, McGinty leads Toomey by 0.7 percent of a point. 

First-term Sen. Toomey is attempting to hold onto a seat that McGinty is fighting hard for. The Philadelphia Inquirer endorsed the Northeast Philly native Sunday, saying she "has the interests of Pennsylvania's people at heart." 

Tonight’s debate, which will be taped at 1 p.m. in Pittsburgh TV station KDKA’s studio and broadcast across the state at 7 p.m., is the first of two. The candidates' second and final debate will take place on Oct. 24 in Philadelphia.

The presidential election has managed to seep into this Pennsylvania race, too. McGinty's campaign has repeatedly skewered Toomey for failing to disavow fellow Republican Donald Trump, especially after a leaked video from 2005 where Trump can be heard making lewd comments about women.

Both McGinty and Toomey addressed the presidential race in a recent set of attack ads. Toomey, who has not decided whether to endorse Trump, said in an advertisement called "Independence" that his criticism of Trump shows he can be independent of his party. 

"I have a lot of disagreements with Donald Trump. I've been very clear about that," Toomey says in the video. "But what's important for Pennsylvanians is having a senator who will stand up to any president's bad ideas."

Meanwhile, McGinty's latest ad, "Dangerous," draws a comparison between the two Republicans:

"Donald Trump and Pat Toomey have plenty in common: They're both putting Pennsylvania women at risk," McGinty says, citing their support to defund Planned Parenthood.