Senate Majority Leader Harry ReidHarry Mason ReidDems search for winning playbook Dems face hard choice for State of the Union response The Memo: Immigration battle tests activists’ muscle MORE (D-Nev.) praised McCain as the key deal-maker in the matter.

McCain has been taking more of a leadership-like role in the Senate lately, working to avert the so-called "nuclear option" on presidential nominees and pairing up with Sen. Chuck SchumerCharles (Chuck) Ellis SchumerDemocrats will need to explain if they shut government down over illegal immigration White House: Trump remarks didn't derail shutdown talks Schumer defends Durbin after GOP senator questions account of Trump meeting MORE (D-N.Y.) and the Gang of Eight to successfully pass immigration reform.

But the longtime senator, who was his party's presidential nominee in 2008, was quick to say he wasn't usurping his party's leaders.

“I don't mean to replace the leadership — usurp it in anyway,” he said, adding “I'm just there to help.”

He said he talked to Senate Minority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellSessions: 'We should be like Canada' in how we take in immigrants NSA spying program overcomes key Senate hurdle Overnight Finance: Lawmakers see shutdown odds rising | Trump calls for looser rules for bank loans | Consumer bureau moves to revise payday lending rule | Trump warns China on trade deficit MORE (R-Ky.) several times over the weekend as he worked with Reid on negotiations.

“He was encouraging me. He wanted to get this done,” McCain said.

Sen. Lindsey GrahamLindsey Olin GrahamDHS chief takes heat over Trump furor Overnight Defense: GOP chair blames Dems for defense budget holdup | FDA, Pentagon to speed approval of battlefield drugs | Mattis calls North Korea situation 'sobering' Bipartisan group to introduce DACA bill in House MORE (R-S.C.), one of McCain's closest friends in the upper chamber, said the Arizona lawmaker was helping out because he “really loves the institution.”

“I think John looks long-term in terms of the Senate. I think he's trying to keep the Senate the way he found it,” Graham said.