T AMPA — Et tu, Christie?

New Jersey Gov. Chris Christie went more than two-thirds of the way through his convention keynote address before even mentioning Mitt Romney; he instead celebrated his own record.

Et tu, Perry?

Texas Gov. Rick Perry, also at the Republican convention here, said he was “absolutely” thinking about another presidential run, in 2016.

Et tu, Santorum?

Rick Santorum, a one-time Romney rival who was given a prime speaking spot by the Romney campaign, invoked the nominee’s name only thrice, choosing instead to recall exploits of his own run for the GOP nomination.

As a rule, politicians aren’t the most loyal lot. It’s often self first, party second and country third. But Romney has a particular problem commanding loyalty, and the Republicans playing Brutus at last week’s convention were just brutal.

Exploiting the tepid enthusiasm for Romney, up-and-comers in the party are using the convention to put down markers for their own presidential bids in 2016. They haven’t gone so far as to disparage Romney — such flagrant disloyalty would be a turnoff — but they are using their moments on stage as auditions. Unfortunately for Romney, the implied assumption is that he’s going to lose.

Christie was particularly brazen in using his keynote address to promote himself on Tuesday night — a day after The New York Post reported that he wasn’t willing to be Romney’s running mate because he thought Romney would not win. Christie extolled his biography (“I am the son of an Irish father and a Sicilian mother”) and, at length, his accomplishments in New Jersey (“We have three balanced budgets in a row, with lower taxes. We did it!”).

On Wednesday morning, Christie felt compelled to explain why his speech had been so self-centered. He told delegates at a breakfast that, because he was preceded onstage by the candidate’s wife, “it allowed me to be able to let Ann Romney talk about Mitt Romney the person.” Christie was thus “freed” to talk about other things — namely, himself.

There were many such auditions. Ohio Gov. John Kasich bragged that “we’re fourth in America in job creation and No. 1 in the Midwest!” Sen. Kelly Ayotte of New Hampshire regaled delegates with the story of her landscaping business, run with her husband — who flew combat missions in Iraq! Ted Cruz, a Senate candidate from Texas, thanked his father, who came to the United States “with $100 sewn into his underwear.”

Other would-be candidates damned Romney with faint praise. Wisconsin Gov. Scott Walker, greeted with a rapturous ovation, touted his victory in a recent recall election and then hailed Romney — for his choice in a running mate. “With the announcement of Paul Ryan as his running mate, Gov. Romney not only showed that he has the experience and the skill to become president, he showed he has the courage and the passion to be an exceptional president,” Walker said.

South Carolina Gov. Nikki Haley, another young star in the party, recounted for the crowd a tepid Romney endorsement from voters who told her that “although we don’t know everything about him, what we do know without a doubt is that we deserve better than what we have today. They are so right.” Haley described Romney as a person who “fixes things” and is “results-driven” — the equivalent of praising him for good attendance.

Other possible 2016 aspirants, including Tim Pawlenty and Ryan, had their auditions Wednesday night, with Jeb Bush and Marco Rubio having theirs on Thursday. Rubio, in a series of TV interviews Wednesday morning, argued that Romney is “a modest person who doesn’t like to brag about himself, but we’re going to do it for him.”

Hopefully, for Romney’s sake, he’ll do it better than Santorum, who once characterized Romney as “the worst Republican in the country” to oppose President Obama. In his convention speech, Santorum sounded as though he were the one accepting the nomination when he recalled his time on the trail (“I’ve gripped hands that work in restaurants and hotels, hospitals, banks”) and remembered his coal-miner grandfather’s “thick, strong hands.”

Virginia Gov. Bob McDonnell matched Santorum’s granddad talk, telling the delegates that the American dream “led my grandfather, a poor farm boy, to leave Ireland a hundred years ago and come to Ellis Island.”

That poor farm boy never could have imagined his grandson would run for president — in 2016.