T AMPA — We have reached a phase of the presidential campaign that could be called the Season of Empty Metaphors.

At their convention here, Mitt Romney and the Republicans held serve. Romney may have failed to hit any home runs with his acceptance speech, but he sprayed the outfield with singles and doubles. Sure, his campaign staff left money on the table by allowing Clint Eastwood to waste valuable network airtime conversing with an empty chair. But the convention did more than enough to turbocharge the base and slingshot the GOP candidate into the homestretch.

Now President Obama and the Democrats are off to Charlotte to generate their own set of clichés. It doesn’t take clairvoyance to predict that when the convention is over, some pundit or politicians will pronounce it as having amounted to three yards and a cloud of dust.

Blah blah blah. The truth is that for all the action-packed, content-free verbiage employed to describe it, the contest between Obama and Romney has been remarkably static. Most polls have the race within the margin of error. Obama has a somewhat easier path to a majority in the Electoral College, but Romney and his allies have an advantage in campaign funds.

For all the effort and money the two camps have spent trying to “define” the opponent, Obama and Romney stubbornly retain the same identities they’ve had all along. Neither is going to change, or be changed, into someone else. I hate to be blunt, but: Deal with it.

GOP convention organizers came away feeling they made great progress in “humanizing” Romney. We know more now about his personal life — the story he told about his father giving his mother a single rose every day was beautiful and touching — but he has made clear that he’s not running to be empathizer in chief. His basic promise is to somehow make jobs shower down from the heavens. Voters must decide whether to believe him or not.

In his speech he made a specific pledge: 12 million new jobs. This sounds ambitious and bold until you do the math. To reach that goal in the 48 months of a presidency would mean an average of 250,000 new jobs each month — a healthy but not outlandish number. In essence, Romney is simply betting that the anemic economic recovery now under way will become a healthy one.

How will he accomplish that transformation? Beats me. Romney is vague when it comes to specifics. But I can safely say that if you believe repealing the Affordable Care Act — and keeping 31 million uninsured Americans from getting healthcare coverage — will do the trick, Romney’s your guy.

In Charlotte, of course, we’ll hear Obama’s side of the story. But we already know it: He took office during the worst financial crisis since the Great Depression, coaxed the economy into stability and then moderate growth, saved the auto industry and, yes, pushed through a package of health insurance reforms that substantial numbers of Americans don’t like.

Obama’s essentially Keynesian, demand-side ideas for boosting the recovery and creating more jobs have been thwarted by Republicans in Congress. And unless the GOP were to keep control of the House and somehow manage to win a supermajority in the Senate, Romney’s ideas — tax cuts, mostly — wouldn’t survive intact, either.

Perhaps the sharpest difference between the candidates — and potentially the most consequential, at least in the short term — is in foreign policy, which neither campaign has chosen to emphasize. Obama is no peacenik, as what’s left of al Qaida can attest. But Romney’s rhetoric, especially concerning Iran’s nuclear program, has grown increasingly belligerent. I worry that his hawkish words betray a dangerous impatience.

But we didn’t hear much about world affairs in Tampa, and I doubt we’ll hear much in Charlotte. Neither party has time for such distractions when there are independent voters to be wooed and swing voters to be frightened out of their wits. Perhaps the most surprising development in the campaign thus far is that Republicans played the “Mediscare” card first — and are enormously pleased with themselves for doing so. Democrats, however, remain confident that ultimately they’ll play it most effectively.

So now, ahem, the ball is in the Democrats’ court. It’s later than halftime but not quite the 11th hour. And as we slouch toward Election Day, “Big Mo” is still nowhere to be found.