House Intelligence Committee Republicans attempted to defy the rules set out by Rep. Adam Schiff (D-Calif.), the committee's chairman, at the start of their questioning period for former Ukraine Ambassador Marie Yovanovitch during Friday's impeachment hearing.

What happened: The GOP's ranking member, Rep. Devin Nunes (R-Calif.), attempted to yield time to Rep. Elise Stefanik (R-N.Y.) for questions, but Schiff shut the move down despite Republicans' protestations because it was a breach of the inquiry's agreed upon-rules.

What the rules say for the public portion of the inquiry:

"Pursuant to H. Res. 660, the Chair and Ranking Member may conduct at the outset of each open hearing extended rounds of questioning for periods of up to 90 minutes, as determined by the Chair and split evenly between the two sides."

"As specified in H. Res. 660, the Chair and Ranking Member may not yield time to other Members during these extended question periods, though either may yield time to Majority and Minority Committee Counsels, respectively."

Between the lines: Both Nunes and Stefanik were well aware of the rules — but most Americans watching aren't — so they hope that the move makes it look like Schiff is controlling the impeachment proceedings with an iron fist.

Go deeper: Live updates on Yovanovitch's impeachment hearing