Nikki Haley endorsing Marco Rubio

The influential Republican governor of South Carolina, Nikki Haley, will throw her support behind presidential candidate Marco Rubio before the state’s Saturday GOP primary, a source with knowledge of the governor’s decision told ABC News.

The endorsement will offer a last-minute boost to the Florida senator in a state where he is trailing behind front-runner Donald Trump and Texas Sen. Ted Cruz.

In the latest CNN-ORC poll, Rubio garnered 14 percent support, compared to 21 for Cruz and 37 for Trump.

Rubio had said Tuesday, “We’d love to have her endorsement. I don’t know if she intends to endorse at this stage … but if we could get it, we would love it. I’m not sure if she’s going to do it or not.”

Other candidates had also been courting Haley’s support.

The South Carolina governor had said Tuesday she was still deciding who would snag her support.

Rubio has been endorsed by two other leading South Carolina politicians: Sen. Tim Scott and Rep. Trey Gowdy.

Haley is scheduled to campaign with Rubio at an event tonight in Chapin, South Carolina.