A primary election voter fills out a ballot at the Augusta Ward 2 polling place Tuesday in the city council meeting room of the Augusta City Center. Joe Phelan/Kennebec Journal

Primary elections, created by referendum in 1911 — the first initiated question placed on the ballot — once riveted Mainers.

During long decades of Republican dominance, winning the primary was tantamount to winning the election, and as many as 10 candidates filed for open congressional seats, back when Maine still had four, then three House members, reduced to two with the 1962 election.

The 1970s featured memorable battles among Democrats. Peter Kyros, the 1^st District congressman who served four terms, had a challenger every time before he was upset in 1974 by 26-year-old Republican David Emery.

Both Joe Brennan, a future governor, and George Mitchell, future U.S. Senate majority leader, contested a 1974 primary won by Mitchell, who then lost to independent Jim Longley in an even bigger upset.

Primaries are less exciting these days. The dominance of money forces candidates into narrow lanes in both parties.

And striking polarization of the electorate makes it even less likely outside-the-numbers candidates can prevail.

Nonetheless, there were some significant results in Tuesday’s voting, shedding light on where voters are leaning as fall campaigns begin.

One that surprises no one is Donald Trump’s GOP dominance. In the most closely watched race, the 2^nd District primary, Austin Theriault blew away Michael Soboleski.

Both are first-term, reliably conservative Maine House members, but there the resemblance ends. Trump endorsed Theriault, and wads of cash from national Republicans didn’t hurt.

How Theriault performs in November is another question. While the race is mostly rated a toss-up, it won’t be easy to beat Democrat Jared Golden, now in his third term.

Golden is that rare Maine congressional candidate who ousted an incumbent — two-term Republican Bruce Poliquin — in 2018. He beat Poliquin again by a wider margin in 2022 after the former congressman skipped the 2020 race.

It’s a rule of thumb that representatives are most vulnerable in a first reelection bid, and Golden has won two. While the 2^nd District is considered likely Trump territory again, Golden garners votes among independents and even a few Republicans.

One issue opponents have raised is Golden’s switch on assault weapons legislation, which he now favors banning after 18 Mainers were massacred in his hometown of Lewiston last Oct. 25.

Whether this stand will cost him votes is uncertain, but it’s unlikely to cost him his seat, especially as shock waves from that dark day continue reverberating.

One issue that unquestionably motivates Democratic voters is access to abortion. The stunning 2022 Dobbs decision by a 5-4 U.S. Supreme Court majority wiped out a two-generations-old constitutional right and prompted virtual bans in 20 Republican-dominated states.

Seven states have already voted to protect abortion rights, and many more will have measures on the ballot in November. All those proposed have passed, and it’s hard to see the new proposals failing in key states like Texas and Florida, though it will take 60% in the latter.

In Maine, the abortion issue ousted Rep. Bruce White, a Waterville Democrat who had an unusual anti-abortion voting record and was seeking a fourth term.

His opponent, Cassie Julia, said she had planned to wait until 2026 to run for an open seat, but changed her mind after hearing her 18-year-old daughter’s concerns — and her campaign was then funded by Planned Parenthood.

Aside from abortion, it’s hard to find anything Democrats would find objectionable in White’s record — this may be a new “single issue” motivation defining voters’ stance.

The Roe v. Wade decision legalizing most abortions in 1973 became a potent campaign issue for Republicans in tight races. Now, the situation has reversed.

Other results show that, beneath the surface, progressive voters are having an impact, as they did in Cape Elizabeth, rejecting two former Democratic House members in favor of newcomer Michelle Boyer.

In Portland House District 118, voters chose longtime school board member Yusuf Yusuf, with no state experience, over former eight-term House member (and former school board member) Herb Adams. A third candidate, Ben Chipman, who held the seat from 2010-16, then served four Senate terms, dropped out a day before the voting; he’s reportedly mulling a bid for City Council.

If Rep. Deqa Dhalac, D-South Portland, and Rep. Mana Abdi, D-Lewiston, win reelection, as seems likely, there will be three Somali-Americans serving in the House, something no one saw coming just a few years ago.

Like other ethnic immigrants to Maine — notably Franco-Americans a century and more ago — these more recent arrivals are finding their way to political success even in a state that remains overwhelmingly white.

In a state rarely seen as a trend-setting, new currents are taking shape.