His opponent in the primary run-off was Republican State Senator Harri Anne Smith.

Young was defeated in a primary run-off against Zell Miller.

Keadle lost in a primary run-off to former congressional aide Richard Hudson.

He fell in a Republican primary run-off to Ron Paul, onece a Libertarian Party nominee for President.

One defeated an incumbent in the primary, three in the primary run-off, ten replaced incumbents who had run for other office.

He finished first in a three-way Republican primary but failed to gain a majority of the votes, forcing a primary run-off in which he was narrowly defeated.

Additionally, Green made a controversial decision during the primary run-off to support Giuliani's unprecedented attempt to extend his own mayoral term, in the name of the emergency of 9/11.

The primary will be held on September 10, 2013, with a primary run-off held on September 24 if no candidate receives 40% in the primary.

Gallego won the primary run-off against Rodriguez.

Todd narrowly won the Democratic primary run-off on July 18, 2006 by a margin of 59 votes - 1,173 to 1,114.