Her withdrawal reflects the energy of the party’s left and voters’ unease with older candidates and paves the way for Graham Platner to challenge Senator Susan Collins in November.
Gov. Janet Mills of Maine, the Democratic establishment’s choice to run for the Senate seat long held by Senator Susan Collins, a Republican, suspended her campaign on Thursday, saying she no longer had the financial resources to compete against Graham Platner, a progressive political newcomer.
Her exit paves the way for Mr. Platner, 41, an oysterman who has led her in polls, to become the Democratic nominee in a crucial Senate race that the party must win to regain control of the chamber.
“While I have the drive and passion, commitment and experience, and above all else — the fight — to continue on, I very simply do not have the one thing that political campaigns unfortunately require today: the financial resources,” Ms. Mills, 78, said in a statement.
She did not mention or endorse Mr. Platner; in an interview on Monday, she had declined to commit to backing him if he became the nominee. Tommy Garcia, a spokesman for Ms. Mills, said on Thursday that the governor “has never voted for Susan Collins, and she will not do so in this election either,” adding that Ms. Mills would “continue to hear and watch how Graham Platner works to earn the support of Maine voters.”
Surrounded by supporters, Mr. Platner claimed victory on Thursday morning in Augusta. After praising Ms. Mills’s experience in the state, he said his campaign was in the process of “taking back what is ours.”