It appears all you hear these days is that Mitt Romney has the nomination locked up, and that his competitors in the GOP primary field need to get out.

This is likely a reaction to a number of polls which indicate that head-to-head matchups between Romney and President Barack Obama show the former running behind the incumbent – something that wasn’t the case with most earlier head-to-head polls. The narrative goes that the bruising GOP race has damaged Romney and reduced his electability on the national stage.

This is presumably because Romney is spending his time running against Rick Santorum and Newt Gingrich rather than Obama, and the longer this lasts the less damage Romney can do to Obama. Continuing this internecine squabbling within the GOP primary is a wasted opportunity, the narrative goes.

The narrative doesn’t impress.

By the reasoning of the narrative, the GOP would have been better off without any opposition to Romney, and the money he’s spent in the primary – money spent in large measure building statewide organizations in each of the primary states – would have done more good sitting in the bank waiting for a media blitz against the president, or alternatively the Romney TV ads hitting Newt and Santorum would have instead hammered Obama.

The narrative seems to neglect the fact that this is April, more than six months before the presidential election. The vast majority of the electorate isn’t really paying attention yet. Sure, partisans on both sides are watching, but the marginal and swing voters aren’t. And they won’t be for a while yet.

So if Romney were to be spending a lot of money and effort attacking Obama six months before the election rather than attempting to define himself as a presidential candidate at this point, he’d be making a mistake.

What’s going on within the GOP primary is as good a use of Romney’s time as any. And for Romney to have to withstand the attacks by Santorum and Gingrich actually toughens him up as a candidate.

Besides, Romney hasn’t earned the nomination yet. He’ll earn it when he gets to 1144 delegates, and not before.

But since Romney’s the presumptive nominee, Santorum and Gingrich and Ron Paul need to be more strategic in how they approach him going forward – and he them. It’s time for everybody in the race to run on their own merits. Santorum and Gingrich need to tout their own visions for the direction of the GOP, and Romney needs to burnish his own credentials as a future president.

Tearing down Obama at this point is a waste of time, though. Certainly the groups like American Crossroads out there should be doing that. But Romney needs to make the case for himself as a plausible winning candidate. He needs to give the public an indication of how he’ll govern and what a Romney White House might look like. He hasn’t really done that to date, which is one reason he hasn’t closed the deal with the GOP electorate (much less the general public). The meme the Romney camp has pushed so far – inevitability as the nominee – has done nothing to define what kind of nominee Romney is, and it has fed concern that he has no political soul.

Thankfully, Romney has inched toward some semblance of definition during the course of this campaign. He has aligned himself with Paul Ryan on budgets and debt, which is a good move even though it will open him up to demagogic attacks by Obama’s camp, and he’s moved toward a reformist view of the tax code – though not to the extent of offering a flat tax or some other more substantial pro-growth change.

He’s a much better candidate than he was in November or December, and the gradual acceptance of Romney as the nominee isn’t just a desire to win – he’s earned that support by moving to the center of the Republican Party. Romney is more conservative than he was four years ago, or even four months ago.

And despite what the polls say, he’s better poised to win in November.

But he’s not finished. Romney needs to make the case in the remaining states. He needs to win Pennsylvania, if he can, or at least get close. He needs to campaign and show strength in New Jersey, Texas and California. He needs to build campaign organizations in those states so that he can fight Obama tooth and nail in them – hopefully to win in Pennsylvania and New Jersey, hopefully to force Obama to expend resources in California.

And Romney needs to make his case to women and Hispanics – voting blocs he doesn’t have to win, necessarily, but he does have to get close. It’s better to do that on the ground campaigning state by state than via satellite in a media bombardment.

And there will be plenty of time to turn the guns on Obama once he’s made it to 1144. By then the public will be a bit more engaged in the election and more ready to pronounce judgement on Obama’s presidency. We all know that judgement will be harsh – the facts don’t permit otherwise. Obama knows this, which is why he’s aimed at dividing the country along racial, gender and class lines as a distraction from that record.

Obama wants to make the election about his opponent. The longer he has to wait before doing that, the better. And the stronger the opponent is, which can only come from actually getting votes from real voters, the harder it will be for Obama to tear him down.

So if Gingrich and Santorum and Paul have the resources to continue the race, by all means let them continue. And let Romney continue to earn the nomination through closing the sale with voters in the remaining primaries. The polls have six months to move in his favor, and they will.