Sen. Lindsey Graham, R-S.C., said on Thursday morning he's "glad" the National Security Agency is secretly collecting millions of telephone records from Americans in an effort to track down terrorism suspects.

“We are very much under threat," Graham said on "Fox & Friends," adding that he is a customer of Verizon, the communications company ordered to turn over the records to the government. "Radical Islam is on the rise throughout the region. Homegrown terrorism is one of my biggest concerns. It is happening in our own backyard, and I am glad that NSA is trying to find out what terrorists are up to overseas and inside the country."

Graham isn't the only Republican defending the Obama administration's broad surveillance program, which the Guardian newspaper exposed on Wednesday.

Ari Fleischer, President's George W. Bush's former press secretary, wrote on Twitter that Obama "is carrying out Bush's fourth term" with drone strikes, phone surveillance and Guantanamo Bay. "Just to be clear & so silent liberals understand, I support President O's anti-terror actions. They're bi-partisan now," he wrote.

Sen. Saxby Chambliss of Georgia told reporters the program is long-standing and legal.

Bush was harshly criticized by the left for collecting phone records without a warrant under the Terrorist Surveillance Program, which began shortly after the Sept. 11 attacks. The Obama administration considers its program different from Bush's because its records collections are approved by a secret order from the Foreign Intelligence Surveillance Court, according to The Wall Street Journal.

Other Republicans offered some criticism of the surveillance. Sen. Roy Blunt, R-Mo., told Politico he's supportive of the federal process to obtain phone records for terror investigations but that the Obama administration seems to be "more expansive and aggressive" than Bush's was. Sen. Rand Paul, a libertarian Republican from Kentucky, wrote that the policy "is an astounding assault on the Constitution."

Democratic reaction has been mixed: Sens. Ron Wyden and Mark Udall have long criticized the NSA surveillance as an overreach, but Sen. Dianne Feinstein of California, chairwoman of the Senate Intelligence committee, said on Thursday that the program protects America and is carefully administered to protect privacy. Sen. Harry Reid said everyone should "just calm down."

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