For the second time in two weeks, a new poll shows Republican Dave McCormick and three-term incumbent U.S. Sen. Bob Casey Jr. (D-Pa.) tied in their Senate race. A new Washington Post survey of 1,003 registered Pennsylvania voters found both candidates had 48 percent support.

“The fact that the McCormick-Casey race is tied at this point is great news for the McCormick campaign,” longtime Pennsylvania GOP strategist Charlie Gerow told DVJournal.

While polls released this week from Emerson, Franklin & Marshall, and New York Times/Siena College gave Casey leads of up to nine points, data showed the contest could become a toss-up with debates right around the corner. That could go a long way toward helping the approximately 12 percent of undecided voters make up their minds.

The polls also found Republican Donald Trump and Democrat Kamala Harris were locked in a dead heat in the Keystone State. Those findings fall in line with other surveys of the race. The RealClearPolitics polling average on Thursday gave Harris a one-point lead.

Previous polls showed Casey pulling in support from Pennsylvania Trump supporters who plan to split their ballots between the two parties. But ticket-splitting in U.S. politics has become less common in recent years, and polls show that trend in the Pennslyvania Senate race may be fading.

GOP strategist Vince Galko of Mercury believes there are definitely Trump-trending undecided voters who are considering McCormick. But, he said, “It’s hard to leave someone you’ve voted for, like Bob Casey, for upwards of three decades to jump ship for someone else.”

One month ago, Casey had about an eight-point lead in the RCP polling average. That’s tightened to around four points.

Tightening polls are adding tension to one of the most high-profile races in the country. It could decide whether Republicans have a 50-50 split with Democrats in the Senate or win an outright majority. If the Senate ends up split, the vice president would cast the tie-breaking vote and give Democrats functional control of the chamber.

The McCormick campaign’s mood was cautiously optimistic. A fundraising email about The Washington Post poll declared “We cannot let up now!”

Casey also used the new poll to raise money.

“This is bad news, folks. With a race this close, we have to fight hard for every last vote,” the Casey campaign said in a fundraising email.

Longtime Democratic campaign strategist Neil Oxman of The Campaign Group expected exit polls to show “12 to 15 percent” of registered Republicans support Casey because of his reputation as a moderate. (However, a FiveThirtyEight analysis found Casey voted for the Biden-Harris administration’s position 99 percent of the time.)

Oxman praised Casey’s campaign for releasing ads early in the campaign that portrayed McCormick as a carpetbagger. “People in Pennsylvania really want to be for someone who’s a Pennsylvanian.”

The McCormick-Casey contest is one of the most expensive races in the country this year. It’s expected to see at least $281.2 million in television, digital, and radio ad buys by Election Day, according to AdImpact. That’s $50 million more than the 2022 U.S. Senate race.

Oxman remains confident Casey will win in November, regardless of the presidential contest.

“The Casey name is still the best brand in Pennsylvania,” he told DVJournal.

One thing that could move the needle is the three debates Casey and McCormick have planned for next month. The two candidates meet face-to-face Oct. 3 on abc27 in Harrisburg. Another debate is planned for Oct. 15 on 6ABC in Philadelphia. Negotiations regarding a third debate in Pittsburgh are ongoing.

Whether they’ll be as ugly as last week’s debate between Trump and Harris is yet to be seen. Galko said Casey and McCormick will likely take a “do no harm” approach to the meetings. He suggested the candidates would go after each other’s records, but didn’t see it devolving into anything vicious.

Whatever the case, there could be plenty of eyes on the Casey-McCormick debates.

“People will pay more attention to the debates because the race is so critical,” said Gerow.