Democrats are maintaining a wide lead over their Republican rivals when it comes to voter registration in Maine, even as both parties enroll more members than either has seen in at least 30 years.

Data from the Maine Secretary of State’s Office compiled after the July 14 primary shows Democrats now have 386,786 members compared to 295,122 Republicans. That gives Democrats an edge of 91,000 votes. Enrollments are at their highest for both parties since at least 1990, the oldest data readily available.

Meanwhile, the number of unenrolled voters, who do not belong to any party, continues to decline and now stands at 339,782, behind Democrats by about 47,000 voters but ahead of Republicans by about 44,000.

The trend is a reflection of an increasingly sharp partisan divide in the U.S., according to those who study elections in Maine and beyond. At the same time, Maine voters are known to cross party lines to broadly support popular candidates despite their party affiliation.

Jim Melcher, a political science professor at the University of Maine Farmington, said the Democratic U.S. Senate primary in July, which followed a Democratic presidential primary in March, has likely boosted the party’s numbers.

“But there have been Democratic gains on the unenrolled for a while now, so this continues a trend,” Melcher said. “The other possibility is that as the 2020 election nears, the public is feeling more polarized and picking a side more often.”

Still he said much of the gains may simply be an “artifact” of primary registrations by voters who wanted to participate. Maine does not allow unenrolled voters to participate in what are essentially party primaries.

Republicans also saw gains since March, largely fueled by the July primary election in the 2nd Congressional District.

“This probably reflects a minor benefit for Democratic candidates generally, but Maine voters are ticket splitters, and this is unlikely to translate into advantages for Ds in every race,” Melcher said.

Melcher said much of the shift may be reflective of voters’ reactions to President Trump.

“Trend line is definitely good for Democrats,” he said. “I think the Trump era has pushed people in the direction of picking sides.”

The state also does not appear to be dramatically shifting to the left, although the most recent statewide public polls have reflected a slight lead for Sara Gideon, the outgoing speaker of the Maine House and the Democratic Party’s nominee to challenge Republican incumbent Susan Collins for her U.S. Senate seat in November.

Collins has long enjoyed broad bipartisan support in Maine, winning her last reelection in 2014 with close to 70 percent of the vote. But her votes to confirm Supreme Court Justice Brett Kavanaugh and to support a federal tax cut that critics have said benefits mainly wealthy corporations seem to be dogging her in the polls. And while Collins said she wouldn’t vote for Trump in 2016, she has dodged the question repeatedly in 2020.

Collins remains the only New England Republican in Congress, following the 2018 defeat of 2nd District Congressman Bruce Poliquin by Democrat Jared Golden in the nation’s  first congressional ranked-choice election.

The sparsely populated 2nd District, where Republicans have largely dominated legislative races, has swung wildly in recent presidential elections. In 2012, President Barack Obama won the district by 9 points, but in 2016 President Trump won it by 10 points.

Maine Democrats first took a substantial lead in voter registrations in March, following a new presidential primary that focused largely on the candidates hoping to unseat Trump in November.

Over the last three decades, Democrats have maintained an enrollment edge over Republicans in Maine, but the current gap is the largest it’s been over that period. Democrats have 31,000 more voters than in 2018 – the year the party recaptured the Maine Senate, increased its majority in the House of Representatives and elected a Democratic governor by a wide margin.

The new mix gives Democrats 36 percent of the registered voters, while Republicans have 27 percent and 32 percent are unenrolled. The Green Independent Party of Maine makes up the remaining 5 percent, with 41,693 voters.

Across New England, Democrats make up 36 percent of the voters in Connecticut, 32 percent in Massachusetts and New Hampshire, and 44 percent in Rhode Island, according to the most recent registration data available from those states. Vermont voters do not register by party affiliation.

But the figures also suggest Mainers are aligning with Democrats more than voters nationally, based on a Gallup poll conducted in July that found 28 percent of Americans affiliate with the Republican Party, 29 percent with the Democratic Party and 38 percent say they are independents.

Depending on their affiliation, party officials in Maine either crowed about or dismissed Democrats’ latest enrollment gains.

“It’s becoming clearer and clearer to Maine people that if they want leaders to represent the values of our state, Democrats are the only option,” Maine Democratic Party Chair Kathleen Mara said. “We’re ready to capitalize on this momentum and elect Democrats up and down the ballot this November.”

But Jason Savage, executive director of the Maine Republican Party, said Democrats largely benefited from back-to-back statewide primary events that did not feature competitive races for Republicans. Savage said his party’s voter registration effort was gaining momentum and Trump’s reelection campaign had already established a foothold in the state with new campaign offices and thousands of volunteers on the ground.

“We are out there in the world hearing from voters, they might be registered Democrats, but they feel their party has left them, so we are going to be focusing on that,” Savage said.