Washington (CNN) With just 12 words, Nancy Pelosi changed everything.

"The President must be held accountable," said Pelosi . "No one is above the law."

That pronouncement came at the close of a press conference Tuesday afternoon, in which the Speaker announced that the House would open a formal impeachment inquiry into Donald Trump's conduct as President.

At the most basic level, what Pelosi's announcement means is that we will -- at some point in the not-too-distant future -- almost certainly have a full House vote on whether Trump deserves to be impeached. And with Democrats solidly in control in the House, Pelosi's action on Tuesday means that Trump is now very likely to be the first president since Bill Clinton back in late 1998 to be impeached. (Clinton was acquitted by the Senate and remained in office. That, at least at the moment, seems the likely outcome for Trump too, because of the Republican majority in the Senate.)

Pelosi, of course, knew what she would be starting if she allowed a formal impeachment inquiry to go forward. The genie is out of the bottle now. The wheels have begun turning and churning to the near-inevitable outcome: A President impeached by the House.

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