Ash Carter vs. Loretta Lynch: Why One Obama Nominee Sailed Through But the Other Is Stuck

— -- Ash Carter sailed through his confirmation process to become the next Secretary of Defense, but there’s one Cabinet nominee whose confirmation is moving forward at a much slower pace in the Senate -– Loretta Lynch, President Obama’s pick to be the next attorney general.

Obama nominated Lynch to succeed current Attorney General Eric Holder on November 8, 2014 -- just over three months ago. Carter, on the other hand, was nominated nearly a month later, on December 5, 2014, and was confirmed on Thursday -- a process that took less than 70 days.

Here’s a look at why Lynch’s nomination is tangled in the Senate while Carter swiftly gained confirmation:

WHAT’S THE HOLD UP ON LORETTA LYNCH?

First, Senate Democrats agreed to not process Lynch’s nomination, which was announced mere days after the GOP netted enough seats to win the majority, until the New Year when Republicans would take control.

But the biggest hurdle to Lynch’s confirmation process is based on President Obama’s executive actions on immigration, which Republicans adamantly oppose and currently are trying to thwart by tying it to a measure to fund the Department of Homeland Security past a February 27 deadline.

Republicans are using Lynch’s confirmation as a tool to raise their displeasure with the president’s immigration plan. Lynch’s confirmation hearing, which was held over two weeks ago, focused less on her qualifications and more on where she stands on President Obama’s recent immigration actions. Senators grilled her on whether she thinks undocumented immigrants in the U.S. have a right to work or a right to citizenship.

Lynch told the committee she believes the administration’s executive actions are legal based on her review of an opinion from the Department of Justice analyzing whether the president has legal authority to take these actions.

Republicans also used the confirmation hearing to take aim at current Attorney General Holder, who has maintained a contentious relationship with congressional Republicans throughout his time leading the Department of Justice.

At one point, Sen. John Cornyn, R-Texas, asked Lynch “You’re not Eric Holder, are you?”

"No, I'm not," Lynch assured Cornyn with a smile. “I will be myself. I will be Loretta Lynch [if confirmed.]"

WHY DID THE SENATE CONFIRM ASH CARTER SO QUICKLY?

Carter’s nomination to lead the Department of Defense, on the other hand, was far less controversial as he coasted through the confirmation process. His confirmation hearing before the Senate Armed Services Committee was held on February 4th, and he was confirmed by the full Senate eight days later.

Sen. John McCain, chairman of the Senate Armed Services Committee, expressed early praise for Carter shortly after Obama had announced his nomination -- signaling the ease with which he’d likely be confirmed.

"He’s not controversial,” McCain told ABC News at the time. "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.”

Carter’s confirmation also comes at a time when the U.S. military’s involvement abroad is a huge concern for Congress. During his confirmation hearing, senators questioned Carter on everything from providing lethal aid to the Ukrainian military to the president’s strategy on the war against ISIS.

Just this week, President Obama asked Congress to authorize the use of force against ISIS – a debate that will dominate Congress in the months to come.

WHERE DOES LYNCH’S NOMINATION STAND NOW?

Lynch’s nomination is currently pending in the Senate Judiciary Committee and is weeks away from even hitting the Senate floor for a full vote

On Thursday, Sen. Chuck Grassley, chairman of the Senate Judiciary Committee, delayed a committee vote on her nomination after several requests from Republican senators to hold over the nomination as they had more questions for her to answer. According to committee rules, any one senator can ask to delay business for one week, and Grassley honored that request.

Since the Senate will be on recess next week, the Senate Judiciary Committee won’t have the chance to vote on her nomination until the last week of February, meaning a vote on her nomination by the full Senate won’t occur until March.

Some Republicans on the committee, like Sen. John Cornyn, R-Texas, and Sen. David Perdue, R-Georgia, have already said they will oppose her nomination, but two Republican committee members – Sen. Jeff Flake, R-Arizona, and Sen. Orrin Hatch, R-Utah – have indicated they will support her nomination.

ABC News' Mike Levine and Luis Martinez contributed to this report.