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A growing handful of Democratic lawmakers have been suggesting it may be time to begin impeachment proceedings against President Trump, especially after he appears to have at least tiptoed up to obstructing justice by allegedly ordering FBI Director James Comey to drop an investigation into Michael Flynn, a day after he fired Flynn as national security adviser. Lawyers don't agree if Trump's purported comments to Comey amount to obstruction of justice, the main charge in both the Nixon and Clinton impeachment cases. But they do agree that impeachment is the only punishment Trump would face.

Impeachment proceedings are still a long shot, not least because they would have to start with House Republicans, and no Republican in Congress is explicitly using the i-word yet. But they are starting to talk subpoenas and making Watergate comparisons, and people who aren't congressional Democrats are beginning to talk impeaching Trump — an idea the public is apparently warming up to. On Tuesday evening, CNN legal analyst Jeffrey Toobin reacted to the report that Trump asked Comey to stand down with "three words: obstruction of justice."

David Gergen, a veteran presidential adviser, went a step further. "I was in the Nixon administration, as you know," he said on CNN, "and I thought after watching the Clinton impeachment, I thought I'd never see another one. But I think we're in impeachment territory now for the first time."

Sen. Angus King (Maine), an independent who caucuses with the Democrats, told Wolf Blitzer on Wednesday that if the Comey memos are "true and confirmed I think you're getting very close to the legal definition of obstruction of justice." When Blitzer asked if we're "getting closer to the possibility of yet another impeachment process," King said, "reluctantly, Wolf, I have to say yes, simply because obstruction of justice is such a serious offense."

King was clear that impeachment would have to be for "high crimes and misdemeanors," because "we don't want to get into the situation where we're charging our president based on any kind of political considerations." And Republicans have to turn on Trump for him to be in any real danger. But as a senior official in the Trump administration and campaign said to The Daily Beast, after the last week, "I don't see how Trump isn't completely f—ed."