Donald Trump is holding a massive rally in Phoenix Saturday to take on illegal immigration — an event that generated so much interest that the campaign had to book a larger venue.

Trump will speak at the Phoenix Convention Center, after aides said demand for tickets exceeded space at the original venue, the Biltmore Resort and Spa.

“We received 4,000 RSVPS in 2¹/₂ hours,” said Trump campaign chairman Corey Lewandowski.

Trump has come under fire for his anti-Mexican comments made at his campaign launch last month.

“They’re sending people who have a lot of problems. They’re bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people,” he said at the time.

The blowback against Trump included NBC, Univision, Macy’s and NASCAR severing corporate partnerships with him.

But Trump also is garnering support from voters fed up with illegal immigration, including in the border state of Arizona. Trump on Friday met in LA with kin of teen Jamiel Shaw, who was shot dead in 2008 by an illegal immigrant who mistook him for a rival gang member.