Democrats' chances of holding on to the Montana seat and the Senate overall have deteriorated further with Sen. John Walsh's decision to drop out of the U.S. Senate race.

The senator announced his decision on Thursday, according to Politico; however, he will remain in the Senate for the rest of his term, which ends in January.

"I am ending my campaign so that I can focus on fulfilling the responsibility entrusted to me as your U.S. senator," Walsh said in a statement. "You deserve someone who will always fight for Montana, and I will."

Walsh said that the allegations of plagiarism had "become a distraction," according to Politco, and it distracted Montanans from the important issues. Back in July, the Montana senator, an Iraq War veteran, faced plagiarism allegations concerning his master thesis during his attendance at the United States Army War College.

According to The New York Times, which broke the plagiarism story, Walsh was elevated to the U.S. Senate after Democratic Sen. Max Baucus was nominated as ambassador to China. The Montana Democratic Party will decide on Walsh's replacement at the state's convention in Helena on Aug. 16.

The news has improved the chances of the Republican challenger, Representative Steve Daines. However, Walsh was already on shaky ground during the election.

"Steve Daines is one of the strongest Senate candidates in the country, was in the process of defeating Senator Walsh and will defeat whichever Band-Aid candidate Democrats can convince to get in the race," said National Republican Senatorial Committee spokesman Brad Dayspring.

Walsh's decision means Democrats in Montana have to choose someone new to run in his stead, according to Chris Cillizza at the Washington Post. The two likely options are former Lt. Gov. John Bohlinger or former state Superintendent of Education Nancy Keenan, both of whom would likely lose, according to Cillizza.

Keenan, who is also the former NARAL Pro-Choice America president, has reportedly declined to run, according to the Great Falls Tribune. On the other hand, the 78-year-old Bohlinger will only run if the party can pledge $10 million to his campaign.