Wyden: Holder letter to Paul represents 'winning a two year battle'

“Does the president have the authority to use a weaponized drone to kill an American not engaged in combat on U.S. soil?” Holder’s letter reads. “The answer to that is no.”

Wyden said Friday that letter represented "a lot of headway" in his push to force the Obama administration to fully disclose the scope and governing principles behind the nation's drone program. Earlier this year, Wyden pushed the administration to explain to Congress under what circumstances it believed it could kill American citizens living abroad.

"There is a sense there is a new political movement emerging in our country and it crosses party lines and it is all about Americans who want to see policymakers strike a better balance between protecting our security and protecting our liberty," Wyden told CNN.

He also said he hadn't received "too much" flak from fellow Democrats for participating in Paul's filibuster. 

Wyden also voiced strong support for the administration's decision to bring the son-in-law of Osama bin Laden to New York to face federal prosecutors, rather than a military location like Guantanamo Bay where he would have faced a tribunal.

"The federal prosecutors have a tremendous batting average in these kinds of cases," Wyden said. "In fact, their batting average is better than these military tribunals."

Republican lawmakers have said Sulaiman Abu Ghaith should not have been brought to the United States.

"When we find somebody like this, this close to bin Laden and the senior al-Qaida leadership, the last thing in the world we want to do, in my opinion, is put them in civilian court. This man should be in Guantanamo Bay," Sen. Kelly Ayotte (R-N.H.) said Thursday.

But Wyden defended the administration's decision.

"What the American people want is tough, effective approaches to make sure that these terrorists are dealt with, that they are behind bars and locked away for the rest of their lives -- that's what we're going to get," Wyden said.