Troy Jackson, a longtime Maine politician who transitioned from Republican to progressive Democrat, formally entered the race for the U.S. Senate on Wednesday following the withdrawal of Graham Platner, who suspended his campaign amid sexual assault allegations he has denied.

Jackson announced his candidacy with a message aimed at rallying working-class voters in Maine and nationwide. “There is a powerful movement of working-class people in the state of Maine, and millions more across America who are ready to send a progressive fighter to the Senate,” he said in a statement. His entry clears the way for Democrats to focus on challenging the three-term Republican incumbent, Senator Susan Collins.

Prior to Jackson’s announcement, several prominent figures had shifted their support in his favor. Representative Ro Khanna of California, who had initially supported Platner, declared his full backing of Jackson on Wednesday. Additionally, Our Revolution, a progressive organization founded by Senator Bernie Sanders, pledged support for Jackson’s campaign shortly after he established an exploratory committee.

Jackson, 58, has a long political history in Maine but remains relatively unknown outside the state. He hails from Allagash, a rural northern community, and has spent much of his career portraying himself as a defender of working people. Over the past two decades serving as a state legislator, Jackson’s political positions evolved notably on key social issues. He now strongly supports abortion and LGBTQ rights and was involved in legislation expanding free school lunch access during the COVID-19 pandemic.

Fellow lawmaker and State Senator Stacy Brenner described Jackson as a passionate advocate who “will fight until the end of the days for the interests of average Mainers.” Jackson’s political career began in 2000 with an unsuccessful run as a Republican for the Maine House of Representatives. He won a legislative seat two years later as an independent and joined the Democratic Party in 2004. He served multiple terms in the Maine Senate from 2008 through 2024 and held the position of Senate president starting in 2018. Jackson’s electoral record includes losses in a congressional race and a 2023 contest for selectman in his hometown.

Jackson has maintained ties to progressive circles, endorsing Senator Bernie Sanders in the 2016 Democratic National Convention and receiving Sanders’s endorsement during his recent gubernatorial bid. While Sanders had also supported Platner’s campaign, Jackson publicly called on Platner to drop out following the sexual assault allegation and expressed belief in the accuser’s account.

Despite his progressive stance today, some Democrats express concerns about Jackson’s earlier positions, particularly on abortion, which opponents highlight as potential vulnerabilities against Collins. During his initial years in the legislature, Jackson opposed abortion rights and supported measures such as mandatory waiting periods and parental notification for minors seeking abortions. According to Maine Right to Life, his voting record earned him high marks from the organization in the early 2000s. However, Jackson’s views shifted over time; in 2023, he helped pass a bill allowing late-term abortions when deemed medically necessary, framing abortion as a health care issue.

Jackson’s record on LGBTQ rights also shows significant change. He voted against legalizing same-sex marriage in Maine in 2009, a decision he has since publicly regretted. Today, he holds a 100 percent rating from Equality Maine, reflecting his strong advocacy for LGBTQ rights.

As Jackson officially joins the Senate race, his campaign aims to consolidate progressive support in Maine and challenge one of the Republican Party’s longstanding incumbents.