Scoop: Trump leans toward endorsing Doug Mastriano for Pa. governor

What we're watching: Democrats are salivating because they see him as beatable in a general election even in a political environment that's extremely favorable to Republicans. Leading Democratic candidate Josh Shapiro even ran an ad highlighting Mastriano in the primary contest.

• With time running out before Tuesday's primaries, Republicans are panicking about the prospect of such a polarizing candidate with limited appeal leading the ticket and are mounting a last-ditch effort to stop him, as Politico first reported.
• Others in the Republican gubernatorial contest include former Rep. Lou Barletta, former U.S. Attorney Bill McSwain and businessman Dave White.

Flashback: In the 2016 primary, then-candidate Trump won Pennsylvania after his more traditional Republican opponents split the remainder of the GOP vote.

Between the lines: Trump is worried about his endorsed Senate candidate Dr. Oz losing, according to two sources familiar with the situation, so his endorsement of Mastriano could be a way of hedging his bets on Tuesday.

• Republicans are also belatedly panicking over the previously unimaginable prospect that Kathy Barnette could win their party's nomination for the open Senate seat in Pennsylvania, as Axios reported.