Gubernatorial candidate Betsy Sweet speaks at the Democratic convention, Saturday, May 19, 2018, in Lewiston, Maine. Credit: Robert F. Bukaty | AP

GARDINER, Maine — Lobbyist and 2018 Maine gubernatorial candidate Betsy Sweet became the first well-known Democrat to announce a 2020 run against U.S. Sen. Susan Collins on Thursday, kicking off a nationally targeted campaign against the four-term Maine Republican.

It’s unclear if Collins will be vulnerable in next year’s election. Her November vote for U.S. Supreme Court Justice Brett Kavanaugh led to a Democratic push to oust her. Her approval ratings have dropped in recent years, but she widely led a likely challenger in a March poll.

That challenger was House Speaker Sara Gideon, D-Freeport, who is likely to announce a run soon after the 2019 legislative session is scheduled to end next week. Secretary of State Matt Dunlap and developer Rosa Scarcelli are among the other Democrats who have said they’re mulling a run, and little-known Saco lawyer Bre Kidman has filed to run as a Democrat.

Sweet is a longtime background player in Maine politics who was the 12th-highest-paid Maine lobbyist between 2008 and 2018. She finished third in the 2018 gubernatorial primary won by Gov. Janet Mills in a ranked-choice race in which Sweet beat out three sitting or former legislators.

Sweet was the only Democrat who used Maine’s taxpayer-funded election system, which won’t be available to her on the federal level. She ran with a progressive agenda including single-payer health care, an hourly minimum wage of $15 and gun control.

In an interview Thursday at a kickoff event in Gardiner, Sweet said Collins “is not representing Maine values anymore.”

“We need someone who is on our side and who really represents Maine people,” she said.

Collins hasn’t run a close race since her first Senate election in 1996, winning by increasing margins culminating in a 2014 victory with nearly 69 percent of votes. She has been ranked by VoteView as the most moderate Republican senator since Maine’s Olympia Snowe left in 2013.

Democrats question whether such rankings mean much under President Donald Trump and a polarized Congress. While Collins cast a pivotal 2017 vote blocking her party’s plan to repeal the Affordable Care Act, she backed a Republican tax-cut package later that year and her Kavanaugh vote may have reshaped her coalition.

Polling from Morning Consult found Collins’ approval rating in Maine dropped from 67 percent to 52 percent between early 2017 and early 2019, and the group found a 46-percentage-point increase in support from Republicans around the vote with an equal decrease from Democrats.

Collins raised $4.4 million for her campaign as of March 31, largely on the backs of large, out-of-state donors. That was more than she raised in her past three races combined and nearly matched two progressive crowdfunds that are being targeted for her Democratic opponents.

Representatives for Collins did not comment Thursday, but Senate Republicans’ campaign arm called Sweet a “radical left-wing activist.”

Sweet hinted at an outsider message, saying while she respects Gideon, the stylistic differences between them would be “moderate, around-the-edges approaches to try to fix things” versus “bold and courageous action.”

Ben Grant, a former Maine Democratic Party chairman who said he would back Gideon if she enters the campaign, said it’s “no surprise” that many are considering the race while hinting at an imminent run from the House speaker.

“Democrats need a Senate candidate with solid values, a proven ability to win elections and record of getting things done once she’s in office,” he said. “I expect that we’ll be seeing a candidate like that join the race very soon.”

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Michael Shepherd joined the Bangor Daily News in 2015 after time at the Kennebec Journal. He lives in Augusta, graduated from the University of Maine in 2012 and has a master's degree from the University...