MSNBC's John Heilemann says Democratic voters sent a powerful message to Trump's cabinet: 'Lawyer up'

MSNBC's John Heilemann said Democrats winning a majority in the House of Representatives is a "really big deal" -- and he urged Republicans to "lawyer up."

The national affairs analyst said the outcome of the midterm election played out how polls suggested it would, with Democrats flipping the House but failing to retake a Senate majority.

"The conventional wisdom was, we were going to get a split decision and this time, unlike 2016, it was actually confirmed," Heilemann said. "I was out with (Showtime's) 'The Circus' over the last weekend, 72 hours I hit eight states in three days, and all in places where there were interesting races to go and see."

Democrats should not lose hope despite some of their marquee candidates, such as Beto O'Rourke in Texas, losing their elections, Heilemann said.

"They're going to wake up not feeling great and not happy that Donald Trump has been rewarded would a bigger majority," he said. "But you've got to keep reminding them that winning control of the House is a really big deal."

He said subpoena power would be a powerful check on the Trump administration.

"It's not just investigating Donald Trump, it's investigating every cabinet member," Heilemann said. "The big message to Republicans is, lawyer up, and they're going to be dealing with stuff over the course of the next two years and they have the power to stop Donald Trump's agenda and they are going to provide, for the first time since the president's been president, an effective check on his ability to pass legislation, to run foreign policy and effective guardrails, because of the investigative power around him."