Undecided voters could push Graham to his first runoff

Sen. Lindsey Graham (R-SC) has spent more than two decades winning Republican primaries in South Carolina without ever being forced into a runoff, but a sizable bloc of undecided voters could test that streak Tuesday in the state’s primary elections.

A Citadel poll published last week found that 18% of likely Republican primary voters are undecided in the race for the GOP Senate nomination, leaving open the possibility that Graham could fall short of the majority needed to avoid a June 23 runoff against leading Republican challenger Mark Lynch.