PHILADELPHIA — All 203 Pennsylvania state House seats are up for reelection this year. But only a handful of races will decide who will take or keep control.

Democrats shocked the state in 2022 when they flipped the state House for the first time in 12 years with a narrow majority. Officials expected the state’s new redistricted maps, which gave Republicans a slight edge over Democrats, to be more competitive, but didn’t expect them to flip it so soon.

House Democrats now control the lower chamber by only one vote, and at times had to lean on moderate Republicans from Bucks County to pass bills they couldn’t get their whole membership to support. Lawmaking halted on multiple occasions throughout the two-year legislative session because of more than a half dozen resignations that put Democrats under their numeric majority.

“We have shown what it means to really respond to the needs of everyday Pennsylvanians, our communities better,” said Joanna McClinton, the history-making House speaker representing parts of Philadelphia and Delaware County in the 191st District, who was elected after Democrats won control.

Gov. Josh Shapiro is campaigning for House Democrats to maintain control. The first-term Democratic governor has a greater chance at getting his shared priorities into law with a Democratic House than if he’s constantly playing defense behind a Republican legislature. (Republicans control the state Senate, and are expected to retain control after the Nov. 5 election.)

Despite the more competitive maps, there are still fewer than a dozen races that are true toss-ups that will decide who controls the state House. National Democratic groups and party leaders have poured millions into keeping control of the state House, and more is expected to be spent in the final five weeks before the election.

There are five Democrats and five Republicans across Pennsylvania who are vulnerable to a challenger due to the makeup of their district, according to an Inquirer analysis of 2020 election data, as well as voter registration.

Here’s a look at the most competitive races around the state on the Nov. 5 ballot and how much leaders are willing to put on the line — for Republicans, to retake the House, or for Democrats, to bolster their narrow majority.

Among the most vulnerable are two Republicans from Bucks County — a Democratic stronghold that Republicans were able to hold on to last election. Rep. Joe Hogan, R-Bucks, who represents parts of Middletown Township, Penndel Borough, and Hulmeville Borough in the 142nd District, won by less than 80 votes in 2022. He is challenged by Anna Payne, a Middletown Township supervisor.

Rep. K.C. Tomlinson, R-Bucks, who represents parts of Bensalem, also faces a challenger from Anand Patel, a former Bensalem Township School Board director and small business owner, in the 18th District.

The last Republican from Delaware County, Rep. Craig Williams, R-Delaware, will also face a tough fight to stay in his seat from Elizabeth Moro, a business owner, in the 160th District. Williams’ district includes parts of Delaware and eastern Chester Counties. It remains a Republican-controlled district, but Democrats feel confident they can flip the seat to make Delco all blue.

Tomlinson’s, Williams’, and Hogan’s seats are the top targets that Democrats think can flip and expand their majority (after protecting the seats they already have), top Democratic legislative leaders said.

“The suburbs offer a huge path forward,” said House Majority Leader Matt Bradford, D- Montgomery. “The realignment that we’ve seen just since 2018 in the suburbs, a wholesale move from red to blue, is encouraging.”

In the Lehigh Valley’s 147th District, Rep. Joe Emrick, R-Northampton, who represents Bethlehem Township and the surrounding municipalities, will face a tough challenge from Anna Thomas, one of the top candidates national Democrats have targeted as a key pick.

In Western Pennsylvania, a Republican incumbent, Rep. Valerie Gaydos, R-Allegheny, will face Hadley Haas, a gun reform advocate and leader of Moms Demand Action in the 44th District in Pittsburgh. Gaydos is part of the politically mixed suburbs of Pittsburgh, as the rest of Western Pennsylvania shifts red.

Rep. Brian Munroe, D-Bucks, faces a tough challenge from Republican Daniel McPhillips in the 144th District. While Democrats say they think they can flip the remaining Republican seats blue, Republicans have an advantage going into November: Republicans outnumber Democrats in Bucks, the most-purple county in the battleground state.

“Bucks County is kind of ground zero,” said House Minority Leader Bryan Cutler, R- Lancaster.

Former President Donald Trump may have received more than 65% of the vote in 2020, but Rep. Frank Burns, D-Cambria, won reelection to an eighth term in 2022. He’s running a Trump-style campaign against Amy Bradley, the president of the local chamber of commerce, in the 72nd District to keep his seat. Burns rejected several of the House Democrats’ more socially liberal policy proposals, but is still seen as a possible pickup for Republicans.

“There’s about a half a dozen seats that President Trump performed very well in, and I expect us to do well in those,” Cutler added.

Rep. Ryan Bizzarro, D-Erie, also represents a Republican-leaning district, though to a lesser degree. Bizzarro, who chairs the House Democrats’ policy committee responsible for setting the Democratic agenda, lost his primary for treasurer in April and now has to hold onto his seat to stay in state government. He faces Republican challenger Micah Goring, a small-business owner and U.S. Air Force veteran, in the 3rd House District.

Two Democratic representatives from the Pittsburgh suburbs in the 16th and 33rd House Districts are also at risk of losing their seats: Reps. Rob Matzie and Mandy Steele. Matzie’s district leans Republican and stretches into Beaver County, while Steele’s leans Democratic. Both are seen as possible pickups for Republicans.