Republicans in the Pennsylvania State House unveiled a newly proposed congressional map Wednesday, taking the biggest step yet toward drawing new districts that will reshape elections for the next decade.

The “citizen map” was drawn by Amanda Holt, a well-known redistricting advocate who successfully sued to overturn the state legislative maps drawn in 2011. It was submitted to the House State Government Committee as part of an open call for maps from the public.

Holt’s map favors Republicans more than the current one, according to an analysis conducted for The Inquirer by the nonpartisan Princeton Gerrymandering Project. The current map was imposed by the Pennsylvania Supreme Court in 2018, after it threw out a Republican-drawn map as an unconstitutional partisan gerrymander. The Holt proposal is less skewed toward Republicans than that 2011 map.

Using results from the 2016 presidential election, when Donald Trump won Pennsylvania by less than 1% of the vote, 10 of the proposed districts would vote for Trump and seven for Hillary Clinton, according to the analysis, which looks only at votes for the two major parties. Using the 2020 election, which Joe Biden won by slightly over 1%, the same 10 districts would vote for Trump and the seven others for Biden.

Being the first map introduced doesn’t mean the proposal will be enacted. Lawmakers will have many opportunities to amend it, and state senators have been working on their own map. That proposal, negotiated by Democrats and Republicans, could be released as early as next week.

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State Rep. Seth Grove (R., York), the chair of the House committee, said he and fellow Republicans chose the Holt map partly because it was drawn by a member of the public known for supporting nonpartisan redistricting. He said he did not know how many Democratic, Republican, and competitive districts the map has.

He also said the map may make some people unhappy.

“There might be some unhappy congressmen as well,” he said. “But that’s a citizen map process, right? You have somebody with no skin in the game draw a map, and you take it. Sometimes you gotta smooth around the edges a bit.”

Overall, Grove said, the map met the criteria he was looking for.

State Rep. Scott Conklin (D., Centre), the top Democrat on the House State Government Committee, said he was “disappointed in the process.” As the committee held public hearings across the state, Conklin said, those who came to testify urged lawmakers not to do a “one-sided map.”

House Democrats had no say in the proposal, he said: “I was really hoping for better.”

Politicians willingly giving up power is almost unheard of, so Grove’s decision to not draw his own map was an unexpected turn. Historically, redistricting has been an exercise in partisan gerrymandering, the process of drawing skewed maps to favor a political party.

New maps are drawn every 10 years to reflect changes in population, and Pennsylvania’s congressional map is a piece of legislation, meaning it must pass through the Republican-controlled House and Senate and be approved by Gov. Tom Wolf, a Democrat, before becoming law. Pennsylvania is losing a seat as a result of population changes, as measured in the 2020 Census, and will have 17 House members starting in 2023.

Holt, a Lehigh County piano teacher, drew widespread attention in 2012 when the state Supreme Court cited her work in its decision to throw out a Republican-drawn map of state legislative districts. A Republican, Holt served on the Lehigh County Board of Commissioners and was later appointed to Wolf’s Redistricting Reform Commission.

In 2011, the Republican-drawn congressional map so favored the GOP that, in election after election, the same 13 districts picked Republicans and the same five districts elected Democrats. That happened even as the state voted for Barack Obama in 2012 and Trump in 2016, and sent Bob Casey, a Democrat, and Pat Toomey, a Republican, to the U.S. Senate.

The state Supreme Court overturned that map in 2018, saying it was skewed so strongly for Republicans that it violated the state constitution’s guarantee that “elections shall be free and equal.”

Pennsylvania is expected to have several competitive congressional elections next year that will help determine which party controls the U.S. House. And in a large swing state with roughly equal numbers of Democrats and Republicans, that makes drawing the congressional map an important way of shaping political power.

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Determining whether a map favors one party can be complicated. There are multiple ways to measure maps, and they can sometimes disagree. Experts generally use multiple methods to get an overall sense.

And some degree of pro-Republican skew may be natural for Pennsylvania’s political geography, given how Democrats cluster into deep-blue cities, including Philadelphia.

On three commonly used measures — known as packed wins, mean-median difference, and partisan bias — the Princeton analysis found the proposed map favors Republicans more than the current one. Looking at an average of two-party election results for statewide races in 2016, 2018, and 2020, seven districts are strongly Republican and five are strongly Democratic, in which a party received more than 55% of the vote. Of the remaining five districts, three leaned Democratic and two leaned Republican.

Those numbers vary when looking at specific elections, such as in the 2018 Democratic wave. But Republicans would generally fare better than Democrats across the range of elections under the proposed map.

The House State Government Committee is scheduled to meet Thursday to review the map, and to vote Monday on amending and approving it. Grove said a full House vote wouldn’t take place until January at the earliest.

Meanwhile, State Sen. David Argall (R., Schuylkill), who chairs the Senate State Government Committee, is preparing to unveil a map he’s been working on with Sen. Sharif Street (D., Philadelphia), the committee’s ranking Democrat.

The senators plan to jointly introduce the map, making it a bipartisan proposal.

“It should be, and it especially should be this year, because we have strong Republican majorities in the House and Senate, and we have a very Democratic governor,” Argall said. “And so if we are going to succeed in passing legislation on this very important subject, it’s going to require bipartisan cooperation.”

Street is said to be interested in running for Congress himself, though he’s also been weighing a bid for the U.S. Senate. Sources familiar with the congressional map emerging from the Senate said it may redraw Philadelphia-based seats in a way that would move U.S. Rep. Brendan Boyle into a new district — potentially creating an opening for Street.

The senators plan to introduce their map as early as next week, said Brittany Crampsie, spokesperson for Senate Democrats.

Argall said he “would certainly hope” to announce the map next week: “We’ve made significant progress, but we still need some more time.”

Argall said he didn’t yet know whether his bipartisan map would be introduced as its own legislation; it could also amend and replace the House proposal entirely. Asked which map — Holt’s or the Senate’s — is more likely to look like the final product, Argall demurred.

“You have to remember, there are 203 members of the House that are going to weigh in on this, there are 50 senators, there’s the governor,” he said. “It’s just impossible to predict.”