TAMPA -- Maybe Ann Romney should have given the acceptance speech, too.

She rose to the occasion with her address to the convention. Mitt missed a big opportunity with his.

With millions of eyes fixed upon him, the Republican Party nominee offered up little beyond a parade of patriotic platitudes. Yes, you expect to hear some of that in every big political speech. But you also hope to hear something beyond that.

We didn’t from Romney. Perhaps if one didn’t know or suspect that he loves his wife and his country and wants the US to have a robust economy, its citizens to enjoy a prosperous future, this speech was an eye opener. But if you’re already familiar with those campaign commonplaces, Romney didn’t leave you much else to grab hold of.

As far as agenda went, what he offered was basically a quick, generic verbal PowerPoint presentation. He favors energy independence, school choice, skills that match jobs, new trade agreements, deficit reduction, helping small business, and the repeal of Obamacare.

He didn’t tie any of that together into a cohesive narrative, let alone an inspiring call to national purpose or greatness.

The address was particularly thin on foreign policy. There, Romney reprised the GOP canard that President Obama had begun his administration with an international apology tour -- a charge that has been roundly rejected by the fact-checkers. Beyond that, a claim that Obama was too accommodating to Vladimir Putin and has thrown Israel under the bus, and some saber-rattling about Iran and its nuclear ambitions, he had little to say.

So why was his speech such an empty-calorie exercise?

The best explanation is that Romney believes he can win simply by keeping things vague and not being Barack Obama.

Indeed, if you reduce his speech to its essence, it comes down to this: The president hasn’t delivered on the future you deserve. I will.

Sometimes that works. But it’s a big gamble to say to voters trust me to do better, when you don’t trust them enough to tell them how.