GOP senator: Hillary Clinton could be impeached

Sen. Ron JohnsonRonald (Ron) Harold JohnsonOvernight Health Care: House passes .3T omnibus | Bill boosts funds for NIH, opioid treatment | Senators spar over ObamaCare fix | 'Right to Try' bill heads to the Senate GOP pushes to change Senate rules for Trump House passes 'right to try' drug bill MORE (R-Wis.) says Hillary ClintonHillary Diane Rodham ClintonRepublicans invest nearly 0,000 in red Arizona district Al Franken: Sessions firing McCabe ‘is hypocrisy at its worst’ Papadopoulos encouraged by Trump campaign staffer to make contact with Russians: report MORE could be impeached if she wins the White House because of the private email setup she used while leading the State Department. 

"She purposefully circumvented it (the law), this was willful concealment and destruction," Johnson told the Beloit Daily News this week, referring to her use of a private email server.

Johnson — who is in the middle of an uphill reelection battle — pointed to two laws tied to willfully destroying or concealing information related to national security, arguing Clinton has violated both of them. 

"I'm not a lawyer, but this is clearly written," he told the local newspaper. "I would say yes, high crime or misdemeanor, I believe she is in violation of both laws." 

The FBI announced last week it was opening a new review into emails potentially tied to its previous investigation into Clinton's private email server. FBI Director James Comey announced in July that, after an initial probe, "no charge are appropriate in this case." 

Johnson, however, called the FBI's initial decision a "corrupt conclusion" and questioned why his Democratic opponent, former Sen. Russ Feingold, is still supporting Clinton. 

"Every election is a binary choice, but she (Clinton) has disqualified herself," he said. "I would love to be voting for Ronald Reagan, and I'm sure the Democrats would rather be voting for Harry Truman, but the reality is that is not our choice."

Asked about defending his own party's nominee, Donald TrumpDonald John TrumpScarborough mocks 'Deflection Don' over transgender troop ban Pelosi condemns Trump's 'cowardly, disgusting' ban on transgender troops Trump moves to ban most transgender people from serving in military MORE, the GOP senator pivoted, asking: "How does Feingold defend Clinton?"

Johnson's campaign pounced on the FBI's decision, using it to put a spotlight on the GOP push for the State Department to release Feingold's emails from his tenure as the special envoy to the Great Lakes region of Africa and the Democratic Republic of the Congo before the election. 

Feingold has backed the emails' release but noted the timing is up to the State Department. 

Johnson currently trails Feingold in the final week of the election. Though the race has tightened, Feingold is leading by an average of nearly 7 percentage points, according to RealClearPolitics. 

Democrats need to net five seats — or four if they also retain the White House — to take back control of the Senate.