'The ultimate sin': Legal expert explains why letting Trump off the hook would be deadly for democracy

Attorney Neal Katyal told CNN on Wednesday that it would be bad for democracy if Congress decided against holding President Donald Trump accountable -- and he argued that merely censuring the president would not be sufficient.

Katyal, whose new book “Impeach: The Case Against Donald Trump” argues for the president's removal, warned that letting the president get away with abusing his office would do lasting damage to America's constitutional order.

"It's the end of an executive branch that lives under the rule of law at that point," said Katyal. "Because if the president can flout it and do it in secret -- it's not just this president, it's any president."

Katyal was then asked by host John Berman about the possibility of censuring Trump for his actions instead of impeaching and removing him.

"I don't think it's enough," he said. "It's a helpful start, but it's really just a start. We're talking about a president doing the ultimate sin: Putting his interests above those of the American people and using his powers... as commander-in-chief."

Katyal then explained that it was bad enough when Trump encouraged Russia to help him win the 2016 election by asking them to release Hillary Clinton's emails, but it's something else entirely when he solicits foreign help when he has the power to withhold aid to countries as president.

Watch the video below.