The Pa. GOP Senate candidates will debate tonight. Here’s how to watch and what we’re watching for.

Mehmet Oz and David McCormick will meet again.

The front-runners for the Pennsylvania GOP Senate nomination will debate tonight for the second time with just two weeks to go until the May 17 primary election. The two have each poured millions of dollars into their campaigns, making the race among the most expensive — and closely watched — in the nation.

Oz, the celebrity surgeon, and McCormick, a former hedge fund CEO, will be joined by Kathy Barnette, the socially conservative firebrand who lags far behind them in the money race but whose grassroots campaign appears to be gaining momentum in the homestretch.

Jeff Bartos, a Montgomery County businessman, and Carla Sands, the former U.S. ambassador to Denmark, will also participate.

The debate will be hosted by Newsmax, a conservative cable news network owned by Chris Ruddy, a longtime friend of former President Donald Trump.

Here’s how to watch and what to watch for:

How to watch: The debate will be broadcast on Newsmax. The channel varies based on cable provider.

Who: Mehmet Oz, David McCormick, Kathy Barnette, Jeff Bartos, and Carla Sands.

When: 8 p.m. Wednesday, May 4.

Where: Grove City College in Western Pennsylvania.

Moderators: Former Fox News anchor Greta Van Susteren will moderate. KDKA radio anchor Rick Dayton will also ask questions.

While the candidates are all on record describing themselves as supportive of stronger abortion restrictions, they’ll likely be pressed on their specific policy positions given the seismic revelation this week that the Supreme Court is poised to overturn Roe v. Wade, according to a draft opinion leaked to Politico.

The opinions of Senate candidates on this issue are not as consequential as those of candidates for governor or state legislative positions. The overturning of Roe would put abortion restrictions in the hands of states. Pennsylvania doctors are currently allowed to perform abortions up to 24 weeks’ gestation, though there are exceptions for medical emergencies.

Pennsylvania does not have a “trigger law” on the books, so a Supreme Court decision to overturn Roe would not mean immediate changes. The General Assembly would have to pass legislation imposing further restrictions on the procedure, and the legislation would have to be signed into law by the governor.

Still, some on the left are pressing lawmakers in Washington to codify a right to abortion in federal law. Either way, it likely just became the top issue heading into the midterm elections, and it’s hard to imagine it won’t come up Wednesday night.

During the first debate, Oz took the brunt of the attacks, a sign the other candidates saw him as their main threat. Oz invoked his endorsement from Trump repeatedly — even a little awkwardly — and wielded it as the others attacked him for his past statements on issues like abortion and guns that now seem out of step with his primary election positions.

» READ MORE: 4 takeaways from Pennsylvania’s first Republican Senate debate

This time around, we’ll be watching to see if Oz leans on that coveted endorsement as much as he did during the first round. Polls conducted after the endorsement showed the celebrity surgeon has not pulled far ahead of McCormick or the other contenders, suggesting the former president’s backing may not have swung the election as much as Oz might have hoped.

The Wednesday debate comes ahead of a Friday rally that Trump is holding with Oz in Westmoreland County.

We’ll also be watching to see how McCormick acknowledges missing out on the nod. His campaign started running ads featuring Trump supporters telling viewers that the former president got it wrong.

Oz and McCormick have long been considered the front-runners with massive ad spending funded largely by their personal fortunes.

But a pair of recent polls shows Barnette, a political commentator and author, nipping at their heels. She’s trying to position herself as the alternative for voters weary of the Oz-McCormick show, and she has proved a sharp debater whose extensive experience on conservative television networks makes her capable of throwing a punch or two.

Also participating in the debate is Sands, who in past debates has targeted Barnette, and Bartos, who is hanging his campaign on a message of restoring economic prosperity to “Main Street.”

Several candidates for Senate promoted election denial or misinformation in the last two debates, and with this one hosted on a Trump-friendly network, there’s no reason to think it will be much different. Most of the candidates have expressed a desire to continue pursuing legislative or legal reviews of the presidential election.

Van Susteren, the moderator, is an experienced commentator and lawyer, and we’ll be watching to see if she presses the candidates on the legitimacy of the 2020 election, which was upheld dozens of times by courts across the country.