Senate Majority Leader Harry M. Reid (D-Nev.) exploited conservative senators’ protest on immigration over the weekend to set up votes on some Obama nominees. (Alex Wong/Getty Images)

Just weeks away from relinquishing his power as Senate majority leader after a humiliating midterm election for Democrats, Sen. Harry M. Reid has positioned himself to end a historically unproductive Congress on an unexpectedly high note.

After Reid (D-Nev.) exploited a weekend rebellion on immigration by rogue Republican senators as a $1.1 trillion spending bill was up against the clock, the Senate will move ahead this week on key executive branch nominations submitted by President Obama that appeared to be stalled not long ago.

The conservative uprising that Reid maneuvered to his advantage has also rekindled concerns about rancor among Republicans. As Sen. Mitch McConnell (R-Ky.) gets set to succeed Reid as majority leader, the familiar GOP problem has again turned attention away from Democrats’ troubles.

Opening the day’s business Monday morning, Reid said the Senate could complete its work “today,” but left open the possibility that the final tasks could stretch on for days.

“We’re going to have to be here to finish our work, whether that’s Tuesday, Wednesday, Thursday, Friday or Saturday,” he said. “So everyone should understand – we can’t be leaving.”

There are hurdles Reid must clear to get what he wants. Although he secured an agreement to allow the confirmation votes to begin, there is no guarantee that the process will move quickly. Reid also wants to pass an extension of tax breaks and renew a terrorism insurance program.

The spending bill, to fund most of the government through late summer, passed Saturday night, but only after a process riddled with complications. The most notable was a push led by Sens. Ted Cruz (R-Tex.) and Mike Lee (R-Utah) to fight Obama on immigration after it looked as if senators were headed home for the weekend.

Reid took advantage of their protest, using the rare Saturday session to advance Obama’s nominees in the confirmation process.

Reid plans to set in motion votes for Vivek Murthy to become surgeon general, Daniel Santos to take a seat on the Defense Nuclear Facilities Safety Board and Frank Rose to serve as an assistant secretary of state.

Then, Reid will set up votes for Antony Blinken to serve as a deputy secretary of state and Sarah Saldaña to head the Immigration and Customs Enforcement agency.

It is unclear whether Republicans will allow Reid to accelerate the process. The nominees face serious GOP resistance, and Republican senators are still angry about Reid’s decision to change Senate rules on confirming nominees. McConnell’s office estimates that the Senate will wrap up its business Tuesday or Wednesday.

If Republicans decline to speed up the process, Democrats run the risk that senators in both parties — especially those leaving office — might start departing Washington for the holidays, making confirmation more difficult.

Senate majority leader Harry Reid (D-Nev.) said Monday on the Senate floor that he had yet to sleep in a Las Vegas-area home he purchased with his wife in May. (CSPAN)

Republicans, meanwhile, are dealing with their own problems. Many of Cruz’s GOP colleagues were furious with his tactics and blamed him for giving Reid an opening to clear Obama’s nominees.

Democrats were gleeful.

“Ted Cruz, by his shenanigans, gave us a wonderful opening to do nominations,” said Sen. Barbara Boxer (D-Calif.). “People need to get into these positions so they can work. He gave us an opening, and we took it.”

The Republican chaos, coupled with the prospect of getting Obama’s nominees confirmed, has given Reid a needed boost in the final days of the least productive Congress in history. After the elections, in which Republicans gained nine seats and seized the Senate majority, some Democrats expressed concerns about his ability to lead.

But Reid’s expertise in arcane Senate procedure served as a reminder of his technical savvy, a tool he could use to frustrate McConnell’s Senate from the minority side.

For McConnell, Cruz’s maneuvering during the spending-bill debate offered a glimpse of the disorder and political pressure he could face as majority leader.

“Republicans should know, unless we can show the American people that we can govern, then we’re not going to elect a Republican president in 2016,” Sen. John McCain (R-Ariz.), a frequent Cruz critic, said Sunday on CBS’s “Face the Nation.”

Asked Saturday whether McConnell should be worried about him next year, Cruz told reporters, “I think every Republican should be worried about one thing, and that is honoring the commitments we made to the American men and women to provide real leadership.”

Among the final batch of nominees Reid is trying to shepherd through this week, Murthy, Saldaña and Blinken have faced strong GOP opposition.

McCain and other Republicans plan to vote against Blinken because he supported and helped implement Obama’s drawdown of U.S. forces in Iraq.

Saldaña, a Dallas-based U.S. attorney, would be the first Latina to lead Immigration and Customs Enforcement. Initially seen as a noncontroversial pick, she had the support of Sen. John Cornyn (Tex.), the chamber’s second-ranking Republican, until she said she believed that Obama’s recent executive actions on immigration were legal. Other Republicans plan to vote against her for making those comments.

GOP senators also have concerns about Murthy’s past roles as an advocate for Obama’s health-care law and for gun control. During his confirmation hearing in February, Murthy was questioned about his support for stricter gun control. Republicans seized on comments on his personal Twitter account, where he said that he was “tired of politicians playing politics w/ guns” and that guns “are a health care issue.”

In response, Murthy said he would not use the surgeon general job “as a bully pulpit on gun control.” But his comments have cost him the support of at least three Democratic senators, while other lawmakers have not signaled whether they will support his nomination.

One nomination that Reid fumbled was that of Carolyn W. Colvin to head the Social Security Administration. Reid pulled back a procedural vote on her because it would have eaten up too much time. Under Senate rules, it would have required 30 hours of debate before clearing a key hurdle.

Now, Colvin’s nomination probably will not come up again until next year, when Republicans control the Senate.

Ed O’Keefe and Paul Kane contributed to this report.