Five states will vote tonight in the Republican presidential primary. And none of them will matter -- at all.

This is what you should be doing during tonight’s primaries. Photographer: Sergio Dionisio/Bloomberg

Former Massachusetts governor Mitt Romney is going to be the Republican presidential nominee. Nothing, literally nothing, that happens tonight in Pennsylvania, New Jersey, Connecticut, Rhode Island or Delaware could change that fact.

Could former House Speaker Newt Gingrich win in Delaware or at least overperform in the First State? Sure. Does it matter? No.

Could Romney be less dominant in Pennsylvania than might be expected of someone who is the de facto nominee? Sure. Does it matter? No.

Romney himself will acknowledge that reality in a way he has been heretofore unwilling to do, according to prepared remarks of a speech he will deliver in New Hampshire tonight.

“After 43 primaries and caucuses, many long days and not a few long nights, I can say with confidence – and gratitude – that you have given me a great honor and solemn responsibility,” Romney is expected to say. “And, together, we will win on November 6th!”

Take a look back at 2008 for evidence that tonight doesn’t matter. Arizona Sen. John McCain essentially clinched the Republican nomination on Jan. 29 when he beat Romney in the Florida primary.

Former Arkansas governor Mike Huckabee went on to win six states between McCain’s Florida victory and Feb. 9. Yes, six! And it didn’t matter a whit.

The race had moved on. Huckabee’s wins were indicative of little other than the fact that he retained a loyal base of conservatives — largely lumped in the South — on which he built his next career as a radio and TV show host.

Like that race, the storylines of this primary have simply reached their natural conclusion. There is no life left in the field. And Republican voters — no matter what they do tonight — have moved on too.

In a Pew Research Center poll released last week, 88 percent of Republicans who supported someone other than Romney for the party’s nomination said they would back him in a general election fight against President Obama. That sort of unanimity among those who didn’t even want him to be their nominee tells you all you need to know.

The Republican race is over. It ended the day earlier this month when former Pennsylvania Senator Rick Santorum ended his candidacy. No matter what happens tonight, remember that fact.