In the minutes after the motion to vacate against McCarthy, Rep. Patrick McHenry, R-N.C., was named as speaker pro tempore, an interim role to lead the chamber until another speaker is elected at a future point.

McHenry is a top McCarthy ally and chairman of the House Financial Services Committee.

He recessed the House for caucus meetings.

Eight Republicans voted to take away McCarthy's gavel.

In addition to Gaetz, who introduced the motion to vacate, the following Republicans voted to oust McCarthy: Reps. Andy Biggs of Arizona, Ken Buck of Colorado, Tim Burchett of Tennessee, Eli Crane of Arizona, Bob Good of Virginia, Nancy Mace of South Carolina and Matt Rosendale of Arizona.

Every Democrat present also supported the motion to vacate.

In a 45-minute roll call vote, the House moved to oust McCarthy as speaker.

The final vote was 216 to 210 in favor of Gaetz's motion to vacate, with eight Republicans joining Democrats.

"The office of speaker of the House of the United States House of Representatives is hereby declared vacant," said presiding officer Rep. Steve Womack.

It is the first time in U.S. history that the speaker of the House has been booted from the post, putting the chamber in unprecedented territory.

Republican rebels appear to have enough votes to remove McCarthy as speaker, given that Democrats joined them, though the vote is ongoing.

Rep. Patrick McHenry, a Republican from North Carolina, was quickly named as speaker pro tempore of the House on Tuesday after McCarthy was voted out.

What does that title mean? It's quite simply somebody designated to preside over the House when the speaker is unable to do so.

After September 11, the House adopted a new rule making it possible to have a speaker pro tempore even if the speaker of the House is unable to name one -- or the speakership suddenly becomes vacant.

The rule was adopted as a measure to ensure "continuity of government" -- so that Congress would not be paralyzed after a terrorist attack. A speaker pro tempore has the power to lead, to pass emergency measures and even a declaration of war.

The position is supposed to be temporary, but there is no explicit limit on how temporary or when a new election must be held to elect a permanent speaker.

But, for now anyway, Republicans are operating on the premise that the House can convene and function even without an elected speaker.

One thing driving the temporary nature of this situation: The speaker of the House is in the line of presidential succession; the speaker pro tempore is not.

-ABC News Chief Washington Correspondent Jonathan Karl