(CNN) – After President Barack Obama asserted Friday that lawmakers opposed to the government's phone surveillance program had a chance to raise concerns, one Democrat said he's been trying to alert the American public for years about attempts to mine their personal data.
Sen. Mark Udall, a Colorado Democrat who has long pushed for greater transparency in the government's counterterror efforts, told CNN he had taken exhaustive steps to unveil the reasoning behind the National Security Agency's collection of phone call information.
"I went to the floor, I offered amendments, I did everything possible short of leaking," Udall said. "And I would never leak any material. I came out with a smaller amount of votes. But I continue to push for this, I've continued to draw attention to it, I'm going to continue to do so today."
Earlier Friday Obama told reporters the phone surveillance program was "subject to congressional oversight and congressional reauthorization and congressional debate."
"If there are members of Congress who feel differently, then they should speak up," Obama said. "And we're happy to have that debate."
Udall said he "did raise questions" about the program, and that he thought it amounted to an overly aggressive intrusion into people's lives.
"I think that we've overreached. I think that we ought to have this discussion and we can find the right balance," he said. "But if the people don't know, how do you have the discussion?"
In 2012, Udall and fellow Democratic Sen. Ron Wyden addressed a letter to Attorney General Eric Holder pressing for greater disclosure of the phone surveillance program, writing that "most Americans would be stunned to learn the details of how these secret court opinions have interpreted section 215 of the Patriot Act."
"As we see it, there is now a significant gap between what most Americans think the law allows and what the government secretly claims the law allows, and this makes it impossible to have an informed public debate about what the law should actually say," the senators wrote. Section 215, reauthorized in 2011, is the section of the law that details parameters for how the government can compel businesses to provide data records.
Udall and Wyden also addressed a letter to FBI director James Clapper in July 2012 expressing concern at the lack of transparency in another section of the Patriot Act.
He also questioned some lawmakers – including House Intelligence Chairman Mike Rogers – who have asserted that government monitoring programs have prevented terrorist attacks.
"There ought to be a discussion because the effectiveness of these programs has been trumpeted. I would suggest, based on what I know, that there are a lot of other reasons that we've thwarted terrorists," Udall said.
In a joint statement with Wyden later Friday, Udall elaborated on his claim, writing of the phone surveillance, "all of the useful information that it has provided appears to have also been available through other collection methods that do not violate the privacy of law-abiding Americans in the way that the Patriot Act collection does."