Sen. Rand Paul has a good chance, in the short term, of succeeding in his filibuster of John O. Brennan to be CIA director.

Senate Minority Leader Mitch McConnell, Paul’s Kentucky GOP colleague, arrived on the floor Wednesday evening to bring extra heft to the 12-hour “talking filibuster,” saying Senate Republicans should not vote to advance Brennan’s nomination until the Obama administration answers Paul’s questions on whether it believes it can use armed drones to target and kill Americans on American soil.

“It is my view that cloture should not be invoked” on the Brennan nomination, McConnell said, referencing a procedural motion that must be overcome for Brennan to receive a confirmation vote. McConnell added that he would vote against confirming Brennan if he gets the 60 votes for cloture when that happens.

Paul yielded the floor after midnight Thursday following a filibuster that clocked in at 12 hours and 52 minutes. Immediately thereafter, Majority Whip Richard J. Durbin, D-Ill., filed a motion to break the blockade on the Brennan nomination, setting up a procedural vote that will ripen Saturday morning. As a practical matter, that could delay confirmation of Brennan until next week at the earliest, but a vote could also come Thursday if Senate leaders agree to hold it earlier. Sixty votes are needed to beat back a filibuster.

Earlier in the evening, Paul demanded a vote on a nonbinding resolution expressing opposition to targeted killings of Americans by drones within the confines of U.S. borders. And he has a good chance of getting one, despite facing an objection on Wednesday evening.

Several hours into his marathon filibuster of the nomination of John O. Brennan to be CIA director, Paul sought consent to end his own debate and set up a vote for Brennan’s confirmation in exchange for a vote on a resolution declaring “the sense of the Senate that the use of drones to execute or to target American citizens on American soil who pose no imminent threat clearly violates the constitutional due process rights of citizens.”

When Paul first signaled he would make the unanimous consent request, floor staff on both the Democratic and Republican sides scrambled, and both Senate Majority Leader Harry Reid, D-Nev., and Whip Richard J. Durbin, D-Ill., emerged on the floor.

Such negotiations usually are carried out behind the scenes, with senators working with leadership to reach agreements to limit debate on measures in exchange for a defined universe of other votes. Making the request in public outside of a negotiated agreement made it all but certain the request would face a Democratic objection. Nonetheless, Paul has demonstrated a persistence in getting the Senate to take similar votes in the past.

Notably, Paul persevered until he got a floor vote on cutting off aid to Pakistan, Egypt and Libya until their governments met prescribed conditions. He kept pushing for that vote until it was finally considered and handily rejected. Paul received a total of 10 ‘aye’ votes as part of debate on last September’s continuing resolution.

Paul has the same leverage point next week, when the Senate is expected to debate an expanded version of a bill to fund the government for the rest of fiscal 2013 that was passed by the House earlier Wednesday. Without action, funding for the federal government would lapse March 27.

In addition, Paul’s floor crusade drew accolades from at least three Senate Republican leaders: Senate Minority Whip John Cornyn of Texas, Policy Committee Chairman John Barrasso of Wyoming and National Republican Senatorial Committee Chairman Jerry Moran of Kansas, all of whom made appearances during Paul’s filibuster.

In addition, the NRSC made a fundraising pitch in support of the effort, highlighting the Twitter hashtag #standwithrand. During the potentially historic filibuster, some conservative activists on Twitter questioned McConnell’s whereabouts the filibuster. McConnell, however, appeared on the floor after 11 p.m. to announce his support for Paul’s efforts.

“What we’re talking about is a resolution that says, what we have been trying to get the president to say, is you can’t kill noncombatants. You can’t kill people in a cafe in Seattle,” Paul said on the floor. “That’s what we’re asking. It is blatantly unconstitutional to kill noncombatants. I can’t understand why we couldn’t get a resolution.”

Before objecting to moving forward on the resolution, Durbin pledged to hold a hearing on constitutional issues related to the drone program. Durbin chairs the subcommittee of the Judiciary Committee responsible for tackling constitutional questions.

“We are scheduling a hearing on the issue of drones because I believe the issue raises important questions, legal and constitutional questions, and I invite my colleague to join us in that hearing if he would like to testify,” Durbin said. “I think this is something we should look at and look closely. That’s why this hearing is being scheduled. I believe at this moment it is premature to schedule a vote on this issue until we thoroughly look at the constitutional aspects.”

Paul did not believe a hearing would be sufficient, noting that lawmakers often hold hearings as a way of forestalling actions on contentious policy questions. While he may never get the level of detail he seeks from Brennan, the Justice Department or the White House, he should have the bargaining power to get his vote.