Donald Trump previewed a coming political battle with fellow Republican presidential candidate Ted Cruz, the tea party senator from Texas who many are predicting is jockeying for Trump's base of support.

"Even Cruz, I think he's going to have to hit me," Trump told a near-capacity crowd of more than 9,000 in Macon, Georgia, during a more than 80-minute speech. "It's going to be a sad day, but we will hit back — I promise."

Republicans in Washington have speculated for months that Cruz, who has largely steered clear of criticizing the GOP front-runner, has been angling for the celebrity billionaire's base of support.