Republican J.D. Hayworth has left his Arizona radio program to primary Sen. John McCain (R-Ariz.), according to media reports Friday.

Hayworth informed the Associated Press of his decision late Friday. Legally, he could not remain a radio host and run for Senate.

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Hayworth was ousted from his Congressional seat in 2006 after 12 years in office by Democrat Harry Mitchell, and has hosted the radio show for the past few years.

"We will formally announce at a later time, but we're moving forward to challenge John McCain," he said. "I think we all respect John. I think his place in history is secure. But after close to a quarter-century in Washington, it's time for him to come home."

He said he wasn't serious about running against McCain until a recent "outpouring of support" from Arizonans asking him to run changed his mind.

"Arizonans have a clear choice _ a clear, commonsense, consistent conservative, or they can remain with a moderate who calls himself a maverick," Hayworth said.

Political experts say they are skeptical that Hayworth can raise enough money to mount a political campaign against McCain.