I think he'd be about 50/50, but I'd probably very slightly lean towards him losing, in part because PA Dems have a pretty decent bench. One data point worth considering is that Toomey ran ~0.6 points ahead of Trump in 2016, and Biden won PA by a point in 2020 (although direct comparisons aren't perfect because of different levels of third party voting).
Just quickly eye-balling the 2020 results in the PA suburbs, it looks the only district where congressional Republicans really ran ahead of Trump was in PA-1, where Fitzpatrick got 56.5% compared to Trump's 46.6%. As a PA suburbanite, my personal hope is that the type of voter who voted Biden/Fizpatrick would have realized that Toomey, unlike Fitzpatrick, is basically an average congressional Republican in terms of ideology (notwithstanding Toomey's occasionally centrist positions on social issues).
Doesn't make sense if Biden won Error county and Pittsburgh suburbs by more than Hillary did, don't you realize in split voting again Shapiro, Fetterman or Lamb would have ran ahead of Biden in Western PA, just because House Rs won the Congressional ballot means zilch when it comes to Pennsylvania Senate race, Toomey almost lost to Kate McGinty if we ran Sestak he would have lost
It does not matter anyways because Rs are gonna win WI, GA, AZ, OH, IA, AK, NC NV Senate races
What do users not understand Biden, Bernie or Booker isn't Hillary, that's why Rs haven't won a single cycle since 2016, Hillary was under a Russian cyber attack, if McCain was still here, here, he spoke out against Trump cyber attack against Hillary. Trump made sure he won, they stacked the Crts, eventhough the Crt gave Biden the Election with ultra Conservative, abd D's still think Toomey would have won, plse