Gideon, a Freeport Democrat serving her fourth term in the Maine House and second term as its speaker, was widely expected to take on the Republican incumbent but first faces a primary battle in June. Collins easily won reelection in 2002, 2008 and 2014 but may be facing her toughest race yet following an intense backlash on her vote last fall to confirm U.S. Supreme Court Justice Brett Kavanaugh.

In an interview with the Press Herald Monday, Gideon, 47, said she didn’t believe Collins was still acting in the best interest of Maine people and had instead become a creature of Washington, D.C. serving mostly the interests of the Republican Party.

“When I think about Sen. Collins, I think she might have been different from the other people in Washington when she was first elected but I have to ask is that still the case,” Gideon said. She said as a U.S. senator she would put Maine and its people first.

Gideon pointed to her legislative service during the eight-year administration of Republican Gov. Paul LePage, with whom she battled on issues ranging from the state budget to making the opioid overdose antidote Naloxone more readily available — including over the counter from a pharmacist.

She said she needed to work with Republicans in the Legislature to achieve those kinds of victories and her efforts in the U.S. Senate, if elected, would be conducted in the same way.

Gideon, who joins at least two other Democrats running for the seat, is the highest-profile politician and the only elected Democratic official to enter the fray. She will likely gain the backing of many of her Democratic colleagues in the State House, creating a ready-made statewide network for her campaign.

Gideon said she intended to serve out her term in the Legislature and as Speaker of the House, saying she did not believe campaigning for the U.S. Senate would be in conflict with her work in the Legislature.

There was no surprise in Gideon’s announcement, as she first hinted in 2018 she was considering a run against Collins. Her campaign, which had been waiting in the wings until the legislative session concluded last week, rocketed into action on Monday. The launch featured intensive social media campaigns on Facebook and Twitter and the release of her first campaign video on YouTube. By the end of the day her campaign Twitter account already had more than 27,000 followers.

Gideon said she was most proud of her work helping to combat Maine’s opioid overdose crisis and her efforts to get Naloxone, known often by its brand name Narcan, into the hands of more people. She said she has received letters from people who lost loved ones to an overdose before the antidote was widely available and from those who have been saved because it was made more available.

Gideon has also led the charge during the legislative session on several bedrock Democratic issues – including expanding access to abortion and offering paid family leave – that could play well with many swing female voters in Maine.

She first became involved in politics when she served on the Freeport Town Council and is married to attorney Benjamin Gideon, a personal injury trial lawyer with the firm of Berman & Simons. The couple have three school-aged children.

Gideon said her time serving both on the town council and in the Legislature has taught her to listen carefully and to act decisively to “make a difference in people’s lives.”

Collins, 66, has not said definitively that she will seek another term but has raised nearly $4 million in campaign funds and is widely expected to fight to retain her seat. She was first elected in 1996.

Her Senate office did not immediately respond to a request for comment Monday.

Collins last won re-election in 2014, defeating Democrat Shenna Bellows, former head of the American Civil Liberties Union of Maine and now a state senator, with more than 68 percent of the vote.

At least two other Democrats have also said they will try to become the party’s nominee for the seat, which will be decided in a ranked-choice primary next June.

Bre Kidman, a Saco attorney and activist, entered the race in April, and earlier this month longtime progressive lobbyist Betsy Sweet, who made an unsuccessful bid for the governor’s office in 2018 announced that she too would seek the party’s nomination.

Sweet issued a statement Monday welcoming Gideon to the race.

“I look forward to a positive and robust primary contest with Sara, with forums and debates in every corner of the state to give Mainers a real choice for who will replace Sen. Susan Collins,” Sweet said.

Collins is also expected to face at least one challenger from the right, as Derek Levasseur, a Fairfield Republican, has said he will seek his party’s nomination in the June 2020 primary.  Lavasseur has registered as a candidate with the Federal Elections Commission but has not reported raising any campaign contributions.

Gideon’s announcement Monday drew a quick response from Republicans locally and at the national level with the National Republican Senate Committee issuing a statement calling Collins “the most independent Senator in the country…”

The committee, a PAC set up to hold on to the Republican majority in the U.S. Senate, also attacked Gideon calling her an “extreme partisan” and claiming she was chosen by “Washington Democrats” including Senate Minority Leader Chuck Schumer, D-New York and Speaker of the U.S. House of Representatives Nancy Pelosi, D-California.

Demi Kouzounas, the chair of the Maine Republican Party, also lashed out in a prepared statement Monday saying Gideon, “has done nothing but work against Mainers’ best interests.”