In a year defined by America's sense of profound uncertainty about the future, the race for the White House just became even more inscrutable. Thanks a lot, Chris Christie.

What could happen in the wake of Christie's endorsement of Donald Trump could be clean or it could be messy. The neat and tidy scenario is simple enough: Propelling Trump to the nomination, Christie starts a stampede of endorsements driven by disgust at the would-be coronation of Rubio — who comes off to his detractors even more smugly, vainly, programmatically, and opportunistically than he did before he discovered the fine art of the sick burn.

The messy second possibility will leave many Republicans reaching for the whiskey. Rather than consolidating the anti-Rubio crowd, Christie could help Trump attract a rogue's gallery of faded law-and-order strongmen from the darkest days of the Bush years: figures like Rudy Giuliani and Bernie Kerik, as the Sunday Times' Toby Harnden suggested on Twitter.

Trump has benefited from a reputation deeper and tougher than any mere brand. But if enough 9/11-era toughs break his way, Trump will be branded politically in the worst possible manner — as the candidate of people, whether urban, suburban, or rural, who are so hot on law and order that they lose touch with the rule of law. Rather than expanding Trump's appeal, the Christie crowd could narrow it, leading the party toward the kind of convention the Democrats suffered in 1968.

It's disorienting enough that it's still too early to tell whether Republicans will take the neat or the sloppy path. But the uncertainty gets even worse.

Rubio is the closest of all the candidates to offering Bush's third term. But with Christie giving Team 9/11 an opening to embrace Trump, the battle over the Bush legacy could turn into something much creepier and complicated than it has been so far. It's now possible to imagine Rubio and Trump fighting over which flavor of Bushism returns to control the GOP. Will it be the soft bigotry of E-Verify, the despotism of the Chamber of Commerce, and the overcompensation of belligerence abroad? Or, in a Trump-Christie era, will it be the Ponzi scheme of the ownership society and the militarization of the homeland?

Although today's electorate views Bushism with suspicion and scorn, deep down, most established Republicans seem genuinely unsure of how else to impress voters. Perhaps this is why even Rubio's most aggressively optimistic rhetoric is always discolored by the hectoring, irritated cadence of the cosmopolitan meritocrat trying to explain once again how good the little people really have it.

Well, the little people are over it. But they might well express their disgust with the Bush years by revisiting the authoritarianism that too often defined it.