Sen. Elizabeth Warren, Geoff Diehl Clash In WBZ Debate

BOSTON (CBS) – Democratic U.S. Senator Elizabeth Warren and her Republican challenger State Rep. Geoff Diehl faced off in their first televised debate on WBZ-TV.

Diehl said Warren is vying to be a presidential candidate, and is not committed to her Senate seat.

"You've been to Georgia, I think just last week," Diehl said in the hour-long debate moderated by WBZ-TV's Jon Keller.

"You were in Pennsylvania and Oklahoma two weekends ago when I was up in Lawrence looking at the gas line explosions and working with the National Guard to get hot plates out. You certainly want to make this a national race for yourself against Donald Trump. This is about Massachusetts."

WATCH: Complete WBZ Senate Debate

Warren, who said she would take "a hard look" at running for president, said Diehl would support President Trump 100 percent of the time, meaning he would be the vote to roll back health care and make cuts to Social Security and Medicare. "It means standing by Donald Trump when he calls white supremacists in Charlottesville 'fine people,'" Warren said.

Diehl, who co-chaired the Trump campaign in Massachusetts two years ago, said supporting the president "does not mean you have to vote how he tells you to vote." He said that he'd focus on bipartisan work in the Senate. "I'm a Massachusetts Republican who's working with Republicans and Democrats," he said.

WATCH: Candidates On Character, President Trump

Diehl questioned Warren's integrity, citing her Native-American ancestry claims and incorrectly taking tax deductions for clothing.

Warren said she's an "open book" and has released 10 years of tax returns. "I've put out my family history, shoot. I even took a DNA test. It's there," Warren said. "And I've also tried to make clear throughout this. I am not a citizen of any tribal nation."

Keller: Both Candidates Should Be Pleased With Performance

Diehl said Warren's actions indicate her future plans. "You are running for president, everybody knows now at this point, it's not a secret at all," Diehl said.

Warren said she has not decided to run for president. "Some people in Massachusetts think, 'that may not be a great idea' and I'm not sure if it is either," Warren said before leaving the WBZ studios.

During the debate, Warren called for Diehl to release his taxes over several years as she has. Diehl said he's not running for president, which is when candidates typically release their tax returns. "I'm not a millionaire like you, Senator Warren. I'm just a guy from Whitman," Diehl said.

WATCH: Candidates On Question 3

The debate became heated when the candidates were asked about their stance on a ballot question that would repeal a 2016 law that protects transgender people from discrimination, including the right to use restrooms and locker rooms that match their gender identity.

Warren said she supports keeping the law in place. Diehl said he wants protections to cover all citizens in Massachusetts. He said the state already has anti-discrimination laws in place and that this law provides a loophole that could be exploited by sexual predators and endanger children.

"This law provides a loophole that someone who is a sexual predator could go into a space, a locker room, and claim that day they identify in a different way and disrobe in front of somebody of the opposite sex," Diehl said.

Warren said Diehl's stance on the issue is wrong. "This is just ugly," Warren said. "Donald Trump is ugly on this topic, the vice president is ugly on this topic and Geoff Diehl is ugly on this topic."

Diehl touted his endorsement by several police unions, including the Boston Patrolmen's Association. "They know that I have the support of them and Elizabeth Warren has made it clear that she has a disrespect of law enforcement that goes to the point where she wants to get rid of ICE," Diehl said.

Warren said she supports law enforcement but there are issues throughout the criminal justice system. "There is a problem, right now, and it is a problem based on race," Warren said, citing studies that show African Americans are more likely to be arrested and more likely to be wrongfully convicted than white people. In August, Yarmouth's police chief blasted Warren for her racism claim.

The election is Nov. 6.