Republican Sen. Markwayne Mullin (R-Okla.) is warning House Republicans that President Biden could not be impeached and removed from office for any conduct or crimes committed before he was elected president in 2020.

Mullin’s statement in an interview with Newsmax pours cold water on a House GOP investigation into Biden’s family’s business dealings, particularly Hunter Biden’s work with foreign companies, while Biden was vice president during the Obama administration and immediately after.

He warned that any high crime or misdemeanor that may serve as the basis for articles of impeachment “has to be committed while he was in office, the current office he holds.”

“So what he did as vice president, what he did in between the two [offices] may not be impeachable,” he said during an interview on Newsmax’s “Wake Up America.”

“If they send us a case, make sure it’s convictable,” Mullin advised. “The bar’s real high, there’s no question about it.”

Many Senate Republicans, including Senate GOP Leader Mitch McConnell (R-Ky.), voted to acquit former President Trump on the impeachment charge of inciting an insurrection against the United States on Jan. 6, 2021, on the technical grounds that he was no longer in office once the Senate tried him in February of that year.

Mullin made his statement two days after the House voted along party lines, 221-212, to approve a resolution authorizing a formal impeachment inquiry of Biden and whether he benefited improperly from his son Hunter’s business dealings with foreign entities.

Hunter Biden declared in a defiant news conference outside the Capitol Wednesday morning that his father was not financially involved in his business.

He said his father was not involved in his work as a practicing lawyer, as a board member of Ukrainian energy company Burisma, or in his partnership with a Chinese private businessman.

A timeline of what House GOP investigators call “the Biden’s influence peddling” focuses on events that took place between 2014 and 2017, while Joe Biden was vice president and shortly after he left that office.

Other Republican senators, including Senate Republican Whip John Thune (R-S.D.) and Sen. John Cornyn (R-Texas), a member of the leadership team, have warned House investigators that there’s little to no chance of convicting Biden in a Democratic-controlled Senate.

Convicting Biden and removing him from office would require 67 votes, which means at least 18 Democrats would have to vote for conviction to produce a result.