PHILADELPHIA — Republican U.S. Sen. Pat Toomey and Democrat Katie McGinty plowed through a fast-paced, final debate Monday night, as they shook off questions at times to focus exclusively on attacking their opponent in the neck-and-neck race.

The candidates fielded 16 questions in the live, televised hourlong debate at Temple University that put the candidates’ deep ideological divide on display. The strident attacks also underscored the closeness of the race.

The first-term Toomey is among the Senate’s most endangered Republicans, running for re-election in Democratic-leaning Pennsylvania after compiling one of the most conservative voting records in Congress.

The GOP is struggling to keep its 54-46 Senate majority, and the neck-and-neck race could tip control to Democrats.

At one point, the two quarreled over whose side had to pull down a TV ad. At times, whole questions went unanswered while they attacked each other. They even squabbled over a question about whether months of negative campaign ads in the expensive race contributed to a general sense of distrust of and distaste for politics and government.

“I’m not sure your respective answers have done much to eliminate distrust and distaste,” moderator Jim Gardner of WPVI-TV in Philadelphia told them.

On a question about gun control, Toomey said he would be better than McGinty at finding compromise, while McGinty said she would be better at leading on the issue.

Other times, McGinty tried to frame Toomey as an out-of-touch Washington insider, suggesting that he had missed “some 90 percent of the key committee hearings and meetings on our critical national security issues” and that he had been in Washington for 18 years — six as a senator — and done nothing to improve health care access.

Toomey, who supports repealing President Barack Obama’s health care law, called McGinty’s claim about missing committee hearings false, and repeatedly sought to paint her as a habitual liar. He several times referred back to her statements made on the campaign trail that she was the first in her family to go to college before a news report emerged in June that showed an older brother had graduated from college years earlier.

Toomey used that example to tie McGinty to Democratic presidential nominee Hillary Clinton, who McGinty has endorsed, campaigned with and backed on key policy positions.

“Maybe it’s Katie McGinty’s problem with the truth that allows her to overlook Hillary Clinton’s chronic lies,” Toomey said.

Meanwhile, Toomey stuck to a tightrope of not endorsing GOP presidential nominee Donald Trump, but not disavowing him, either.