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Sen. Richard Shelby, R-Ala., on Sunday downplayed President Donald Trump's calls for Ukraine and China to investigate former Vice President Joe Biden and his son, Hunter Biden, saying, "Things happen."

During an interview on ABC's "This Week," host George Stephanopoulos asked Shelby, "Setting aside whether it's an impeachable offense, do you think it was proper for the president to solicit foreign interference in our election?"

"Well, I don't know that has been actually proven," Shelby said.

Stephanopoulos then pointed to Trump's public calls to have Ukraine and China investigate the Bidens over Hunter Biden's business dealings in the two countries.

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Shelby said the calls were just political statements.

"I didn't say it was OK," Shelby said, adding: "People do things. Things happen."

"Well, this is the president of the United States," Stephanopoulos responded.

"Well, still the president of the United States is human," Shelby said. "And he's going to make mistakes of judgment and everything else. They have historically, both parties, both from the beginning of our republic."

Shelby added that he does not believe Trump's conduct was impeachable, but he said, "I still think we should wait and see what comes out in the trial itself."

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As the Senate trial is set to begin Tuesday, Trump has insisted that none of his conduct with regard to Ukraine was wrong, tweeting last week: "I JUST GOT IMPEACHED FOR MAKING A PERFECT PHONE CALL!"

The House passed two articles of impeachment last month. The first article charged Trump with abuse of power for pushing Ukraine to announce investigations into the Bidens and other Democrats as he was withholding nearly $400 million in military aid to the country, along with an official White House visit for Ukrainian President Volodymyr Zelenskiy. The second article charged Trump with obstructing Congress' investigation into his efforts.