Democratic leaders are again taking the temperature of their caucus on whether to finally go “nuclear” and change the Senate rules after Republicans blocked another judge Monday night, aides said.

Conversation about the “nuclear option” between leaders and the rank and file began as members trickled back into town before a failed 53-38 cloture vote on the nomination of Robert L. Wilkins to the D.C. Circuit Court of Appeals.

Though Democrats have threatened to change Senate rules on multiple occasions this Congress — and have yet to blow up procedure to remove the 60-vote hurdle for nominees — talking about rules change again would at a minimum appease frustrated progressive members and, at its most dramatic, alter the way the Senate does business.

After the vote, Sen. Jeff Merkley, D-Ore., a top proponent of changing the rules, released a pointed statement urging leaders to consider moving forward.

“When will we say enough is enough? Repeatedly over the past month, a minority of Senators has blocked qualified nominees by abusing the Senate rules. The rules on nominees are not working, and we need to change them,” Merkley said in the statement. “This court will rule on the critical protections that we put in place to protect hard working families from the predatory practices of Wall Street. We cannot let a minority of Senators block qualified nominees and endanger the important reforms that have been put in place to protect Oregon families.”

President Barack Obama also released a statement after the vote, decrying Senate Republicans for obstructionism (although it’s worth noting that Sens. Susan Collins, R-Maine, and Lisa Murkowski, R-Alaska, voted with Democrats.)

“When it comes to judicial nominations, I am fulfilling my constitutional responsibility, but Congress is not. Instead, Senate Republicans are standing in the way of a fully-functioning judiciary that serves the American people,” Obama said. “The American people and our judicial system deserve better. A majority of the United States Senate supports these three extraordinary nominees, and it is time for simple yes-or-no votes without further obstruction or delay.”

The question is how to get that up-or-down vote Obama is demanding without a rules change. And in recent weeks, Democrats certainly have been ramping up their PR efforts to build political support for enacting such a change.

Last week, Democratic senators held a news conference decrying GOP obstruction on D.C. circuit nominees on the basis of gender. And on Monday night, a pair of senators joined members of the Congressional Black Caucus to highlight minority appointees — such as Wilkins and Federal Housing Finance Agency nominee Rep. Melvin Watt, D-N.C. — who have been blocked.

Senate Majority Leader Harry Reid, D-Nev., has filed separate motions to reconsider each of the three failed D.C. circuit nominees, but for some Democrats who see the political writing on the wall — that 60 votes will be impossible to attain – that might not be enough.

“I am very hopeful that Sen. Reid will be able to get … these votes on the floor so that they can be voted up-or-down, but I think we have a constitutional responsibility, particularly with judges, to vote on the nominations of the president,” Sen. Benjamin L. Cardin said at the CBC news conference.

Cardin declined to respond directly when asked what Reid’s next move might be.

“You’d have to ask Sen. Reid that question,” Cardin said.

Niels Lesniewski contributed to this report.