WESTERVILLE, Ohio (KDKA) — Two Pennsylvania Democrats are warning the 12 candidates at tonight’s Democratic debate to think about how their words help or hurt them in our region.

The debate — in Westerville, Ohio — is the first since an impeachment inquiry began against President Donald Trump.

“He’s shooting holes in the Constitution,” said former Vice President Joe Biden earlier this month, “And we cannot let him get away with it.”

Impeachment is sure to come up but also watch for attacks on U.S. Sen. Elizabeth Warren, the latest front-runner in some polls.

“I am ready to go on offense,” declared Warren.

And eyes will be on 78-year-old U.S. Sen. Bernie Sanders, who just suffered a mild heart attack.

The other candidates are looking for a break-out moment.

Besides the original 10 candidates, Hawaii U.S. Rep. Tulsi Gabbard and California billionaire Tom Steyer will be on the stage.

One challenge, says some local Democrats, is for candidates to avoid saying something that comes back to haunt them in Western Pennsylvania.

Two Democrats, U.S. Sen. Bob Casey and U.S. Rep. Conor Lamb — both who won Democratic counties that President Trump carried in 2016 — are warning the candidates to watch what they say so as not to lose moderate-to-conservative Democratic votes in this region.

WATCH: KDKA’s Jon Delano previews tonight’s Democratic debate.

“I would just advise all these candidates to think a little more carefully about the issue and about the people you are trying to represent,” Lamb told KDKA political editor Jon Delano.

Issues like guns, trade, steel, and coal come to mind, and especially fracking of natural gas — which some candidates want to ban.

“The false choice is that you have to choose fracking over good climate policy,” Casey said.

Casey says natural gas is a clean fossil fuel that must be regulated but not banned because it has made the United States “less dependent and which creates, as we know, lots of jobs in Pennsylvania.”

So far, U.S. Sens. Kamala Harris and Cory Booker, Gabbard, Warren and Sanders, have called for a ban on fracking.

Lamb, who represents the cracker plant in Beaver County, is blunt.

“My advice is that they’re wrong,” Lamb said.

“They are wrong about whether they can do that, first of all. I don’t think the president has the authority to ban fracking. But they’re also wrong about whether that is the right idea,” added Lamb.

Trump carried every county in western Pennsylvania except Allegheny, and the ultimate Democratic nominee will need to do better in the Democratic counties than Hillary Clinton did.

“We say we are the party of the working class,” said Lamb, a Mt. Lebanon Democrat. “We don’t pick favorites. Energy jobs are middle-class jobs. People are working hard and buying their first house, putting their kids through school, on the jobs that have been provided by natural gas development and by the cracker plant.”

Which is why words in debates can come back to haunt candidates.

A fifth debate has already been scheduled in Georgia for Nov. 20, the week before Thanksgiving.

Although the rules have been tightened, at least eight Democrats have already qualified.

The Iowa Caucus is Feb. 3, followed by the New Hampshire Primary on Feb. 11.