MISSOULA, Mont. -

Montana Sen. John Walsh has officially left the race for the U.S. Senate race amid allegations that he plagiarized a thesis paper at the U.S. Army War College in 2007.

According to Communication Director Terri McCoy, the Secretary of State’s Office received a Withdrawal of Candidacy fromWalsh.  According to Montana law, the Democratic Party has until August 20 to appoint a candidate to fill the vacant seat.

Click here to read the official document.

Gov. Steve Bullock appointed Walsh in February to replace Sen. Max Baucus, who was appointed U.S. ambassador to China.

Walsh served 33 years in the Montana National Guard. He was the state's adjutant general when Bullock, then attorney general, tapped him to be his running mate in the 2012 governor's race. Walsh served as lieutenant governor, his first elected position, for just over a year before his Senate appointment.

Politico reporter Manu Raju says the scandal that brought down Walsh's campaign all but guarantees a republican victory in November, but most pollsters weren’t giving Walsh a chance, even before the scandal broke.

"John Walsh would have had a hard time winning this race, given the environment," said Raju.

The uncertainty over the senate race in Montana has only bolstered the confidence of the National Republican Party, seeking to take control of the senate for the first time since 2006.

"Republicans need to pick up 6 seats to win the senate, with 3 that are almost certainly going to include West Virginia, South Dakota, and Montana," said Raju.

Raju says it will be difficult now for Walsh to have any influence in Washington

"Really we're looking at very little impact that John Walsh can do, given that he is still a freshman senator,” said Raju. “He's serving in one of the most gridlocked congresses of all time."

It's a tidal change from the situation less than 2 years ago, when Democratic Senator Jon Tester won re-election, and was flanked by fellow Democrat Max Baucus - at the time one of the longest serving senators in Washington D.C.

"The seat that Max Baucus had has not gone to a Republican since 1913,” said Raju. “This is a sign of major change, and probably a regaining of prominence among republicans who have been on the outliers of Montana"