Kelly said the "intense personal ambition" of Trump White House staffers, who backstabbed and leaked to the press, was "out of hand."
Democrats now have several options before them, including a subpoena for the returns.
From the Democratic frontrunners to the dark horses, here's a complete list of who has officially announced a 2020 bid for the White House.
Congress' inability to override Trump's veto means that, for the time being, the national emergency declaration to build a border wall will go on as planned.
Biden has yet to announce his candidacy, but his support could crumble the moment another candidate emerges who demonstrates electability.
Rep. Elijah Cummings and the House Oversight Committee are investigating violations of the Presidential Records Act in relation to Kushner's work.
Trump's former personal lawyer Michael Cohen had recently testified that the president directed him to threatened schools not to release information.
President Trump's 2020 campaign backtracked on a statement on 5G wireless technology after it appeared to contradict Trump administration policy.
Trump previously denied playing a role in the process and said he was "never involved with the security."
Pete Buttigieg, the openly-gay mayor of South Bend, Indiana, is running for president. In a conversation with INSIDER, he revealed why he's not afraid of the odds.