The breakdown of the Senate is all but set. And a handful of races in California — and President-elect Donald Trump’s personnel decisions — seem likely to determine how much wiggle room Republicans will have in their probable House majority.

Arizona Senate: Almost a week after the election, the Associated Press called the open Senate race for Democratic Rep. Ruben Gallego over GOP nominee Kari Lake. His lead at the time of the call stands at about 72,000 votes. It’s a crucial win for Democrats, who will now have a minority conference of 47 seats in the Senate.

Pennsylvania Senate: Incumbent Sen. Bob Casey (D-Pa.) chipped away at GOP Sen.-elect David McCormick’s lead, but the Democrat still trails by 35,000 votes after more ballots came in on Monday. The Casey campaign isn’t conceding until the counting wraps, but he faces long odds to erase McCormick’s advantage. The AP called the race for the Republican several days ago. “Ruben Gallego and David McCormick have been invited to attend orientation,” a spokesperson for Majority Leader Chuck Schumer said Tuesday morning.

Battle for the House: Republicans have secured 214 called seats by the Associated Press — and currently lead in races that would give them 222 seats. Some of those may not hold, though. Here’s an overview of some of the most competitive seats:

California 27th: Incumbent Rep. Mike Garcia (R-Calif.) said in a statement Monday night that he had conceded to Democrat George Whitesides, ensuring a flip of a GOP-held seat. Ballot drops have consistently broken in the Democrat’s favor as the process continues. 
California 47th: Democrat Dave Min expanded his lead over GOP nominee Scott Baugh to more than 3,200 votes — or more than one percentage point — for this open seat. An estimated 82 percent of votes have now been counted. 
California 13th: Democrat Adam Gray continues to chip into Rep. John Duarte’s (R) lead in this contest, which appears likely to come down to the wire. The incumbent currently leads by just under 3,000 votes with 62 percent of ballots counted. 
California 45th: A set of ballots dropped on Monday from Orange County broke heavily for Democrat Derek Tran, dropping Rep. Michelle Steel’s (R) lead to 3,908 votes. There are an estimated 16 percent of ballots still outstanding in the contest, so this one is likely to be a nail biter. 
California 41st: Longtime incumbent Rep. Ken Calvert (R) declared victory on Monday as his lead over Democrat Will Rollins stood at more than 7,500 votes. Rollins isn’t conceding yet, though it seems he’d need everything to break his way to overcome Calvert’s lead. 
California 22nd: Incumbent Rep. David Valadao’s (R) lead stands at just under 10,000 votes with an estimated 77 percent of ballots counted in this contest against Democrat Rudy Salas. 
Arizona 6th: Rep. Juan Ciscomani’s (R-Ariz.) lead swelled to nearly 5,000 votes over Democrat Kirsten Engel as more votes are tallied in this swing Arizona district. The AP has not formally called the contest, but this looks like a sure GOP hold. 
Alaska at-large: Observers are still waiting for ballots from rural Alaska to be tallied, but incumbent Rep. Mary Peltola (D) faces long odds to make up a 10,000 vote gap with GOP challenger Nick Begich. One thing to watch: If Begich doesn’t get to 50 percent, the state’s ranked-choice voting system kicks in. 

One other thing to watch: Maine officials will run the state’s ranked-choice voting procedures Tuesday at 1 p.m. (watch on YouTube, if you’re into that). Incumbent Rep. Jared Golden (D) leads his GOP challenger Austin Theriault by more than 2,000 votes but came up short of an outright majority, triggering the ranked-choice voting system.

Things could get interesting fast for the GOP majority: Two House Republicans — Reps. Elise Stefanik (N.Y.) and Michael Waltz (Fla.) — have already been tapped by Trump for senior roles, opening up special elections for their seats. Waltz’s role doesn’t even require Senate confirmation, so he’ll vacate his seat immediately.

Called races by the AP Monday afternoon: Rep.-elect Cleo Fields (D-La.); Rep. Mark Takano (D-Calif.)