Graham Platner, the Democratic Senate candidate in the US state of Maine, has suspended his campaign after a string of controversies, including an accusation of sexual assault, plunged one of the most competitive races for the 2026 midterm elections into turmoil.The suspension by the former US Marine and oysterman was announced in a video posted on social media."We believe for the movement to continue, it can't be me. For that reason, we are suspending campaign operations," Mr Platner said in the 11-minute video."This is incredibly difficult because I know that some will think it's an admission of guilt, and it most certainly is not."Graham Platner announced the suspension of his midterm election campaign in a video posted to social media. (Reuters: Supplied/Graham Platner for Senate)The move is likely to complicate Democrats' efforts to win control of the Senate in the November 3 elections. Republicans currently hold a 53-47 majority in the US Senate.The race in Maine, one of the Democrats' best opportunities to pick up additional Senate seats, will now focus on how the party finds a replacement candidate to challenge incumbent Republican senator Susan Collins.Mr Platner said the process to replace him needs to be "open, transparent and democratic" and to reflect the will and values of people who supported him.Graham Platner, pictured with his wife Amy Gertner, has already weathered a number of scandals. (AP Photo: Robert F Bukaty)He also lashed out at Democratic leaders in Washington DC."People in DC need to stay in DC," he said."Decisions should not be made by people in places of political power."Although Mr Platner had never held elected office before, progressive leaders promoted him over Governor Janet Mills, who was favoured by the Democratic establishment.Ms Mills dropped out of the race in late April as Mr Platner consolidated support among primary voters eager for a more combative candidate and willing to overlook his chequered past.Shortly before Mr Platner clinched the Democratic nomination in the June 9 primary, there were reports he had exchanged sexually explicit messages with other women while married, and that he had become physical with a previous girlfriend during an argument.Many Democrats had already questioned his fitness for office before Politico reported on Monday, local time, that a woman accused him of forcing her to have sex with him nearly ⁠five years ago.Jenny Racicot, who lives in Maine, told Politico she had been in an on-and-off relationship with Mr Platner but cut off contact with him after that night in 2021 and told him the encounter was not consensual.CNN followed with a report that the woman accused him of entering her home without permission and raping her while he was intoxicated.Graham Platner says the process to replace him as a candidate needs to be "open, transparent and democratic". (Reuters: Amanda Sabga)After the story was published, Mr Platner, in a video released on social media, denied the allegation as "categorically false" but said he would be "taking the time to reflect on the best path forward" for his campaign.On Tuesday, The Washington Post reported a former girlfriend of Mr Platner's said he repeatedly removed condoms during sex without her consent, an allegation that Mr Platner's campaign called "categorically false and politically motivated".Democratic leaders and senator Bernie Sanders have called on Mr Platner to withdraw from the race.Prominent members of Congress rescinded their endorsements of him and leaders of the Democratic Senatorial Campaign Committee said they would withhold funding from the race if Mr Platner remained on the ballot.State law includes a provision for Democrats to replace Mr Platner before the general election.The state Democratic Party held an emergency meeting on Wednesday where more than 100 state committee members signed off on holding a nominating convention in the event of Mr Platner's withdrawal.According to the statute, party officials may select a new nominee if a candidate who won the primary withdraws by 5pm on July 13. The replacement candidate must be named by July 27.The departure may signal the end of Mr Platner's rapid political rise, as he tapped into a current of progressive politics by promoting a universal national healthcare system and working-class themes, while directing criticism at billionaires and concentrated wealth.Mr Platner has faced a series of other controversies, including offensive Reddit posts he apologised for and a now-covered tattoo that resembled a Nazi symbol.The Wall Street Journal reported that Mr Platner's wife, Amy Gertner, had told the campaign her husband sent sexually explicit texts to several women early in their marriage.In a video message, Ms Gertner said the two had a "great marriage".Mr Platner has acknowledged poor behaviour in the past and asked for forgiveness, saying he struggled with alcohol abuse and mental health issues after military deployments in Iraq and Afghanistan.AP/ Reuters