(CNN)On Monday afternoon, Colorado Sen. Cory Gardner said the Senate should vote to expel Roy Moore in the increasingly-unlikely event the Alabama Republican nominee wins a special election on December 12.
Roy Moore would be first senator expelled in 155 years
"If (Moore) refuses to withdraw and wins, the Senate should vote to expel him, because he does not meet the ethical and moral requirements of the United States Senate," Gardner, who runs the GOP Senate campaign arm, said in a statement.
That process could begin the moment Moore was officially seated in the Senate following his victory. (The Senate has no ability to block a senator being seated.) Moore would be expelled if two-thirds of the senators present voted for him to be removed.
If that came to pass, Moore would become just the 16th senator ever expelled from the chamber, according to the Senate's historical records. Fourteen of the 16 were expelled for supporting the Confederate cause during the Civil War. Tennessee Republican Sen. William Blount was expelled in 1797 after he was outed as the ringleader of a plot to attack Spanish-controlled Florida and Louisiana. The last Senator to be formally expelled from the Senate was Indiana Democratic Sen. Jesse Bright in 1862.
Another 15 Senators have been considered for expulsion but either resigned, saw their Senate terms expire before any action was taken or survived the two-thirds majority requirement vote.
Here's a look at the eight Senators in the last 100 years who have faced expulsion -- in reverse chronological order:
* Oregon Sen. Bob Packwood (R): Packwood faced a series of sexual assault and abuse of power allegations. On September 7, 1995, the Senate Committee on Ethics recommended Packwood be expelled. He announced he would resign the next day and officially left the chamber on October 1, 1995.
* New Jersey Sen. Harrison Williams Jr. (D): Williams was the central figure in the FBI's Abscam sting in which an agent impersonated an Arab Sheik who lavished Williams (and other members of Congress) with money in exchange for access and favorable treatment. Williams was indicted in 1980 and found guilty in 1981. Like Packwood, the Committee on Ethics recommended he be removed. He resigned on March 11, 1982.
* North Dakota Sen. William Langer (R): On the day he was to be seated in the Senate in 1940, Langer was accused of bribery and other charges by a group of North Dakota citizens. A Senate Select Committee tasked with looking into the allegations recommended expulsion. But Langer survived -- with just 30 Senators voting to expel him.
* Louisiana Sen. Huey Long (D)/Louisiana Sen. John Overton (D): Long was elected first in 1930 but played a major role in Overton's election two years later as well. The allegation was that Long -- through his control of the apparatus of state government -- used government resources as campaign workers to help Overton. Two Senate committees tasked with looking into the charges couldn't find their way through the thicket of allegations, and no expulsion vote was ever held for either man.
* Montana Sen. Burton Wheeler (D): Wheeler was paid by someone to represent their interests before the Department of the Interior. (He was a senator when he agreed to do this.) But a Senate committee looking into the set-up found that the client's interests were at the state level not the federal level -- alleviating Wheeler of an obvious conflict of interest. Just five senators wound up voting to expel him in 1926. By 1940, his image was sufficiently rehabilitated to be considered a potential running mate for Franklin Roosevelt.
* Michigan Sen. Truman Newberry (R): One year after beating Henry Ford -- yes, THAT Henry Ford -- to win the seat in 1918, Newberry was indicted on charges of widespread violations of state and federal campaign finance laws. Newberry was convicted in 1919, but that conviction was narrowly overturned by the Supreme Court in 1920. In January 1922, Newberry survived a Senate expulsion vote, 46-41. But Ford -- and his immense resources -- threatened further legal action. That threat forced Newberry's hand and he resigned in November 1922.
* Wisconsin Sen. Robert La Folette (R): La Follette delivered a speech in Minnesota in Setpember 1917 in which he bashed the United States' involvement in World War I. Some in Wisconsin didn't take kindly to that sentiment -- the US had just entered the war -- and asked that the Senate remove him. In January 1919, the Senate dropped the issue -- after being unable to find witnesses willing to speak on La Follette's alleged disloyalty to country. By a 50-21 vote, the Senate opted to drop all charges against the Wisconsin Republican.