President Obama Plans to Nominate Ashton Carter as Next Defense Secretary

— -- President Obama intends to nominate Ashton Carter to replace Chuck Hagel as Defense Secretary, according to a source familiar with the decision.

An announcement is likely by the end of the week.

Sen. John McCain, who will become chairman of the Armed Services Committee, said he does not anticipate Carter will face a tough confirmation fight.

"He’s not controversial,” McCain told ABC News. "He’s qualified and he’s the last man standing, but he’s been around long enough to know he will have little or no voice in the crucial decisions on national security.”

Sen. Carl Levin, the outgoing chairman of the Armed Services Committee, told ABC News that Carter was "highly qualified." He said confirmation hearings should begin immediately.

McCain said he wouldn't object to the hearings starting before Republicans take control of the Senate next month. But he said the hearings would likely focus less on Carter's qualifications than on President Obama's strategy on ISIS. McCain, who has been one of the loudest critics of the president's foreign policy, said today that it barely mattered who the president selected as his fourth defense secretary, because all decisions are made inside the West Wing.

“All decision making is amongst a handful of people in the White House who only have one thing in common – that they don’t know anything about the military," the Arizona Republican said.

Just last week, Homeland Security Secretary Jeh Johnson was a top contender for the Pentagon post, but a source close to Johnson said last night that he was no longer under consideration.

Previously Senator Jack Reed, D-R.I., and Michele Flournoy told the White House they were not interested in the job.