Washington (CNN) Former GOP Rep. Joe Walsh, a longshot candidate for the Republican nomination for president, on Sunday called President Donald Trump a "traitor" for asking Ukraine and China to investigate former Vice President Joe Biden and his son, Hunter, and again argued Trump should be impeached for asking other countries to "interfere in our election."

"There's enough we know now to vote to impeach this President. He stood on the White House lawn this week, Jake, and told two additional foreign governments to interfere in our election. That alone is impeachable. This is a strong term I'm going to use. But I'm going to say it on purpose: Donald Trump is a traitor," Walsh, who represented Illinois, told CNN's Jake Tapper on "State of the Union."

The strong comments from the former Republican congressman come as Trump faces a widening impeachment inquiry in the House of Representatives. Most current congressional Republicans have remained silent and declined to speak out in opposition to the President's comments last week that he wants both Ukraine and China to investigate Joe Biden and his son, Hunter. Walsh had previously said he supports Trump's impeachment and said again on Sunday that congressional Republicans should also "get behind" it.

There is no evidence of wrongdoing by either Joe or Hunter Biden.

Walsh told Tapper that he is "not accusing this President of treason," but he said Trump has betrayed the nation.

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