Tester was on Capitol Hill for the 2021 United States Electoral College vote count on January 6, 2021, when Trump supporters stormed the U.S. Capitol. He was in his office in the Hart Senate Office Building when the Capitol was breached. Along with his staff, Tester was evacuated to an undisclosed location for safety. He called the storming a “despicable and dangerous attack on our democracy” and "a coup by domestic terrorists", and blamed Trump for instigating it. He also said that impeachment of Trump was unlikely in such a short period of time before Joe Biden's inauguration on January 20. He called fellow Montana senator Steve Daines an "enabler" of the attack, as Daines supported Trump's unproven voter fraud claims.