Michigan’s too-close-to-call primary is getting all the headlines tonight but Mitt Romney’s clear victory in Arizona shouldn’t be underestimated.

Republican presidential candidate and former Massachussetts Gov. Mitt Romney speaks during a press availability following a visit to his Michigan campaign headquarters on February 28, 2012 in Livonia, Michigan. (Photo by Justin Sullivan/Getty Images)

(Twenty-eight of Michigan’s 30 delegates are doled out by congressional district — two for each of the 14 seats. The other two are handed out proportionately based on the statewide results.)

If you buy the notion that we are headed for an extended delegates fight — and it’s hard to see the race ending anytime in the near future — then Romney’s Arizona win already means that he has had a good night.

Of course, this race for president isn’t solely a battle for delegates — a series of trench warfare battles fought in each state. There’s also a symbolic national race going on — one that is influenced far more by momentum than raw numbers.

In that latter race, Romney’s Arizona victory won’t mean anything unless he can also notch a win in Michigan, which, according to exit polling, is nip and tuck between Romney and former Pennsylvania Senator Rick Santorum.