Rudolph Giuliani, the lawyer for President Donald Trump, told Fox News anchor Laura Ingraham that the Congressional Democrats should be sued for bringing their impeachment investigation against the president.

Giuliani thinks there is no legal ground for probing the president’s action in the Ukraine scandal. He called the impeachment effort a “witch-hunt” that is worse than the infamous former Sen. Joseph McCarthy’s (R-Wisconsin) search for communists in the 1950s.

Giuliani believes House Democrats have crossed a line by listening to the president’s private calls to foreign leaders. He said that the Democrats have meddled in and hamstrung Trump’s conduct of foreign policy.

Despite Giuliani’s threats, Congress members have immunity from being sued for their official activities.