Jackson first ran for the
Maine House of Representatives in 2000 for Maine House District 151, as a
Republican, narrowly losing to Marc Michaud, a
Democrat, 2,017–2,172. Two years later, he was elected to House District 151 as an Independent, defeating the incumbent Michaud 2,171–1,176 in a race with no Republican candidate. He was the first non-Democrat to represent the area since 1978, but joined the Democratic Party in early 2004. That year, after Maine's post-census legislative redistricting, Jackson ran for re-election in the new House District 1 as a Democrat. He won a resounding victory against Republican Paul Berube, by a margin of 3,486 to 1,248. He was re-elected to the State House unopposed in 2006. In 2008, Jackson ran for and won Maine State Senate District 35, defeating Republican Daniel DeVeau 11,188–6,593. He would be re-elected in 2010 by defeating DeVeau 7,525–5,620 in a rematch, holding the seat amidst a Republican
wave that saw the GOP claim its first
government trifecta in Maine since 1963. He would be re-elected again in 2012 by a narrow 8,521–8,016 margin over Republican
Peter Edgecomb. Democrats regained control of the Maine Senate in that election, and in December 2012, Jackson was elected Assistant Majority Leader of the State Senate after the Democrats. On July 10, 2013, Jackson was elected Majority Leader of the Maine Senate after the departure of fellow Democrat
Seth Goodall, who resigned to accept a presidential appointment overseeing the
New England region of the
Small Business Administration. On July 1, 2013, following incumbent Democratic Congressman
Mike Michaud's decision to explore
running for
Governor, Jackson announced he would
run for
Maine's 2nd congressional district, which had been Michaud's seat since 2003. On June 10, 2014, Jackson
lost the primary to fellow State Senator
Emily Cain, receiving 21% of the vote to Cain's 79%. Cain would go on to lose the general election to Republican
Bruce Poliquin. On January 25, 2015, Jackson was elected as a member of the
Democratic National Committee. This gave him a
superdelegate vote at the
2016 Democratic National Convention. He was one of only a handful of superdelegates to endorse and vote for Vermont Senator
Bernie Sanders over former Secretary of State
Hillary Clinton. and a week later he was chosen by his fellow Democrats to be the Senate Minority Leader. He would be re-elected as Senator of the 1st District in
2018,
2020, and
2022, becoming the Senate President as the Democrats would gain the majority in 2018 and retain it in 2020 and 2022. Jackson left the Maine Senate following the
2024 election due to term limits. He was succeeded as Senator for the 1st District by Republican
Susan Y. Bernard and as Senate President by Democrat
Mattie Daughtry. On March 7, 2025, Jackson announced he was formally exploring a run for
Governor of Maine in the
2026 election. He officially announced his candidacy on May 19. == 1998 Logging Blockade ==