YouTube screenshot of Donald Trump Jr.
On Wednesday, Donald Trump Jr. fired off a tweet mocking former Vice President Joe Biden's fitness for office.
Former Congressman Joe Walsh (R-IL) promptly hit him back — reminding him of his father's controversies, and calling him a "traitor" to America.
Walsh, a lawmaker first elected in the 2010 tea party wave, has become one of President Donald Trump's most vocal critics from the right, even launching an unsuccessful primary challenge to try to deny him the GOP nomination for 2020.
