Only one of the top five members of the bipartisan congressional hierarchy still sits on the fence about launching a punitive strike against Syria: Mitch McConnell, the Senate minority leader.

The Kentucky Republican emerged from the White House on Monday as the only member of the bicameral leadership group still uncommitted to voting in favor of legislation authorizing military action.

McConnell looks to be taking as much time as he can. He’s weighing his political considerations back home, where an isolationist stance would provide clear short-term benefit, against the pressures of his leadership role at the Capitol, where he’s spent almost three decades as a Republican voice for a hawkish defense posture and an interventionist foreign policy.

The senator was one of the group of a dozen Hill leaders who spent an hour in the Cabinet Room hearing President Barack Obama and his aides lay out their case for why Congress should endorse plans for missile strikes, the president’s proposed response to last month’s chemical weapons attack outside Damascus. The attacks killed more than 1,000 people and, the administration says, was surely the work of Bashar al-Assad’s embattled regime.

Speaker John A. Boehner and House GOP Leader Eric Cantor both emerged to declare they would vote to support the president, offering crucial support in the corner of the Capitol where Obama’s Syria plan (along with everything else he proposes) faces the most skepticism.

Both of the Hill’s top Democrats, Senate Majority Leader Harry Reid and House Minority Leader Nancy Pelosi, reiterated their solid support for what the president wants.

McConnell, though, stayed away from the cameras and issued only a brief and noncommittal statement before returning to Kentucky, where he plans to remain until the summer recess ends a week from now.

“I appreciate the president’s briefing today at the White House and would encourage him to continue updating the American people,” the statement said. “While we are learning more about his plans, Congress and our constituents would all benefit from knowing more about what it is he thinks needs to be done — and can be accomplished — in Syria and the region.”

Spokesman Don Stewart said McConnell would not stake out a position before seeing the final legislative language, which he had no expectation of helping shape. With Obama’s acquiescence, the measure is likely to be narrower than what the White House initially asked for, probably by restricting the duration of the attacks and limiting the use of ground forces.

As importantly, McConnell’s ambivalent comment echoed a theme that has come through in the statements from several other top Republicans, including several who have promised to vote with the president: Obama will have to win the authorization votes, which are on course for next week, on the strength of his administration’s evidence and the persuasiveness of his own arguments that a strike is in the United States’ own interest.

Members of the GOP leadership won’t try to “whip” members of the rank and file to their side in the traditional sense of applying political pressure, mainly because modern congressional custom is that decisions about using military might are considered “conscience votes.” But, this time, the hands off approach is also because the leaders worry their persuasive tactics could backfire. They could lose as many votes as they gain, especially from rambunctious conservatives, while at the same time leaving the impression that the party’s top voices were laying claim to an equivalent ownership stake in the Syria policy, which for now remains decidedly unpopular with the public.

McConnell’s time in the Senate would suggest he’d not be shying away from either result now.

He has had a solid record as floor leader in holding his caucus nearly unified, even on roll calls when GOP senators were given a “free pass” to vote without guidance from the top. He also has an even longer record, much of it formed during his long run as the top GOP appropriator of foreign aid, as a promoter of a robust foreign policy that combats oppressive governments.

McConnell was an early and emphatic “yes” vote in favor of both the Iraq War congressional authorization in 2002 and the Persian Gulf War resolution in 1991, and for the past decade he’s been one of his party’s consistently forceful defenders of the long and political unpopular military involvement in both Iraq and Afghanistan.

But none of that history is all that useful to him as he prepares to run for his sixth term next year — a campaign that will begin with a Republican primary against an outsider businessman, Matt Bevin, who’s base of support is among the sorts of domestically libertarian, internationally isolationist and anti-establishment voters who have fueled the big rise of the tea party forces in Kentucky.

Their hero, of course, is the state’s other senator, Rand Paul, whose preparations for a 2016 presidential run looks almost certain to include leading the chorus of GOP conservatives who will be seeking to defeat the Syria military strike authorization.

For the next week, at least, McConnell has reason to worry more about the vigor of his Senate colleague’s rhetoric than he does about the criticism from Alison Lundergan Grimes, the Kentucky secretary of state recruited by the Democrats to run for the Senate next fall.

“Being mum on issues of national security is not being a leader” is her sound bite in recent days.

It’s a tough riposte to rebut. But it’s also hard to argue with the notion that keeping your powder dry until the end of the battle is a reliable way to remain a survivor. And that’s a political title McConnell earned long before he got his leadership mantle.