The dead giveaway, if it wasn’t a total head fake, was when Paul D. Ryan showed up to begin his ninth term in the House sporting a blossoming beard.

No one so hirsute has been elected president, or even run a sustained national campaign, since Benjamin Harrison back in 1888 — so obviously the facial hair was the clearest sign yet the Wisconsin Republican was taking a pass on 2016. Unless he was signaling the opposite: That he was getting ready to emulate James A. Garfield, another in the string of bearded 19th century presidents and the only sitting House member ever sent to the White House.

Turns out, the lengthening stubble had nothing to do with what the Capitol was chattering about last week. Ryan revealed Monday that he’d definitively ruled out running in the next presidential race and had made up his mind over the holidays, when he had decided not to pack a razor for his latest deer-hunting trip. (When he returned, he thought it wise to retain the beard as a good-luck talisman for as long as his beloved Green Bay Packers stay alive in the NFL playoffs.)

That so many were speculating in such a silly way about Ryan’s future is understandable, given how topsy-turvy the preliminary stage of the GOP presidential campaign is proving to be. But it’s easy to identify a long list of reasons why Ryan concluded 2016 is not his year.

For other lawmakers, staffers and lobbyists on the Hill, the most important reason may also be the most obvious. Ryan just picked up the Ways and Means gavel, arguably the single most influential piece of hardware in the committee system, and it would become a significantly weakened policymaking instrument as soon as he betrayed interest in any other position.

“Our work at the House Ways and Means Committee over the next few years will be crucial to moving America forward, and my job as chairman deserves undivided attention,” was the central point of his demurral statement.

The most comprehensive rewrite of the corporate tax system in three decades, which Ryan has declared the top priority of the chairmanship he’s taken after four years running the Budget Committee, was going to be an enormously heavy lift in the best circumstances. Its prospects haven’t gotten appreciably better because of Ryan’s widely anticipated decision. But they would have gotten a whole lot worse had he done the unexpected.

There is essentially no way he would have been able to get the process off the ground while raising money and courting voters in the early primary and caucus states. And he could have perished any thought about finding Democratic negotiating partners on a historic deal during the climactic months of a 2016 campaign.

At a minimum, the bifurcated obligations would have been logistically impractical, even for someone of Ryan’s noted stamina.

More fundamentally, it would surely have proved politically impossible to commingle the myriad demands of a national race with the almost infinite number of competing interests in top-to-bottom changes to the IRS rule book.

Ryan seems to have given his new committee’s staff a heads up that he understood these realities and wasn’t planning to combat them.

CQ Roll Call learned that he told his Ways and Means team he has both a two-year plan and a backup four-year timetable for getting the tax legislation done — a tacit acknowledgement he’s counting on staying chairman in the first two years of the next administration. Had he not sent such signals, it’s not likely Ryan could have recruited some of the top staffers he’s brought aboard — most visibly Brendan Buck, a former press secretary for Speaker John A. Boehner who gave up a lucrative new career as spokesman for the health insurers’ trade association to return to the Capitol as committee communications director.

Ryan seems to have telegraphed his decision a while back to Republican National Committee Chairman Reince Priebus. Only a few hours elapsed between the non-candidacy declaration and the RNC announcement of Ryan as chairman of one of the party’s premier fundraising arms, the Presidential Trust, for the 2016 cycle. The money will be spent in coordination with the GOP ticket, mainly to help party organizations in battleground states with get-out-the-vote efforts, so there’s no way Priebus would give the job to a politician plotting to be the presidential nominee.

The congressman’s timing also dovetails cleanly with Mitt Romney’s wave of activity making clear he’s seriously interested in another presidential bid. The two appeared to forge a genuine bond as running mates, and the 2012 GOP nominee for vice president declared last fall that he wouldn’t run for the top job in 2016 if Romney wanted another shot.

And even if Romney begs off in the end, there’s Gov. Scott Walker of Wisconsin — another genuine Ryan friend who’s expected to conclude his moment is now and would be really grateful if his buddy deferred his ambitions.

Timing is enormously important in politics. And the congressional record is filled with rising stars who, by their own behavior or their reactions to others’ decisions, were never able to realize their apparent national potential. Ryan has been prominent in the GOP firmament since he first took his House seat 16 years ago, and he’s still got two weeks to go before his 45th birthday. In theory, he’s got a couple of decades to pull the presidential trigger and several potential avenues (speaker, senator, governor, Treasury secretary) for staying relevant in the interim.

But, if a Democrat wins next time, 2020 may look awfully tempting — and provide a curious historical bookmark.

Ryan will be approaching his three-term limit as Ways and Means chairman, a ready-made “up or out” moment for his House career. He may have some significant achievements on taxes, trade or social entitlements to boast about. But even if not, he’ll presumably remain the principal spokesman for his party’s views of fiscal policy, which are sure to stand in sharp contrast to those of that hypothetical Democratic sitting president.

On top of that, it will be the 140th anniversary of the election of Garfield, another congressman from the Midwest (Ohio) who had chaired two prestigious committees (Appropriations and the forerunner of Armed Services) and was propelled to national prominence around his 50th birthday.

All that would be left to cement the parallel is for Ryan to grow another beard.

The 114th: CQ Roll Call’s Guide to the New Congress

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