Pennsylvania voters go to the polls today to pick nominees for the midterm elections. They’ll join with voters in Idaho and Nebraska for today’s primaries, but most of the focus will fall on the Keystone State, as Democratic hopes for a House majority will rest in large part on picking up new seats in the Keystone State’s court-imposed redistricting. Before we take a look at the House, though, Republicans have a big choice coming up in what might be a competitive Senate race. Which candidate has the best chance of defeating Democratic incumbent Bob Casey Jr in November?

Pennsylvania GOP Rep. Lou Barletta appears poised to win the Republican nomination to take on Democratic incumbent Bob Casey this fall. Barletta was an early Trump ally, and the president recorded a robocall for him ahead of Tuesday’s primary, according to Politico.

Barletta has spent $2 million so far, including $503,000 in the first three and a half weeks of April alone, according to his pre-primary FEC report. His primary challenger, state Rep. Jim Christiana, has spent a total of $262,000, including $36,000 during the pre-primary period.

Trump carried the Keystone State by less than a point in 2016, making Casey among the more vulnerable Democratic incumbents up for re-election. But Democrats are confident he’s in a strong position. Casey has more than $10 million in his campaign coffers — the highest by any Senate candidate in the state’s history, according to his campaign.

Trump carried Pennsylvania in part because Hillary Clinton took the state for granted. Casey won’t make that same mistake, nor will the DSCC — although they will have their hands full defending 25 other Democrat-held Senate seats this fall. That’s why Casey’s own fundraising matters so much in this race.

At least at the moment, a Barletta-Casey race looks like a long shot for the GOP, but Barletta’s probably the best choice for a challenger that the GOP has in its bullpen. Early polling on this matchup shows Casey with double-digit leads over Barletta, at least in late March and early April, the most recent head-to-head polls available at RCP’s aggregation. One potential warning signal for Democrats, though, is Casey’s level of support; he got 48% in Morning Call’s poll and only 43% in Franklin & Marshall, well below the 50% safety level an incumbent would like to see.

What about the House races? The Hill focuses on five primaries, but they warn that the Democratic primary in PA-07 might create enough infighting to derail their hopes in taking full advantage of the redistricting:

Progressives are backing Susan Wild, an Allentown city solicitor endorsed by EMILY’s List, or Greg Edwards, a pastor supported by Sen. Bernie Sanders (I-Vt.).

Meanwhile, Democratic District Attorney John Morganelli is running as a centrist. But Morganelli’s vocal opposition to illegal immigration and previous praise for President Trump have made him open to attacks from the left. …

Women Vote, the EMILY’s List super PAC, has spent more than $370,000 boosting Wild and opposing Morganelli.

Billionaire mega-donor Tom Steyer’s group, NextGen America, chose the race to make its first foray into primaries this cycle, backing both Edwards and Wild. The group’s $100,000 investment in advertising is aimed at opposing Morganelli.

United Together PAC, which has ties to the bipartisanship-focused group No Labels, is opposing both Wild and Edwards, spending about $350,000 against them.

There seems to be more infighting over which candidate is sufficiently progressive in PA-04 and PA-05, but both new districts are heavily Democratic and their nominee will almost certainly win regardless of any damage taken in the primary. That may not be the case in PA-01, which went from tossup to a Hillary +2 district, making it tougher for Republican Rep. Brian Fitzpatrick to hold his seat in suburban Philadelphia. The two Democrats have savaged each other as illegitimate in the primary fight, with claims of carpetbagging and (gasp!) secret Republicanism getting exchanged. Fitzpatrick may yet luck out.

For Republicans, the fight in PA-14 will be most interesting. Rock Saccone, who just made a name for himself in losing a slam-dunk special election in the old 18th district against Conor Lamb, was picked by party convention as the endorsed candidate in PA-14. Nevertheless, he’s being challenged in the primary by Guy Reschenthaler, who lost to Saccone in the special election primary. Reschenthaler is being backed by Sen. Pat Toomey. Regardless of who wins this primary, the GOP should hold the seat in this new district, given that it went for Trump by 30+ points, but … we thought the same thing about the special election in the old 18th, too.

Outside of Pennsylvania, the only other primary of interest is the Democratic contest in Nebraska that will choose the challenger to Sen. Deb Fischer. The leading candidate, Roll Call suggests, is a city council member from Lincoln, Jayne Raybould. At the end of last month, Raybould had $310,000 cash on hand; Fischer had $2.6 million. Raybould wants to hammer Trump on tariffs, which might be a good strategy, but Trump won Nebraska by more than twenty points. Raybould’s contest is likely going to be a sideshow, both today and in November.