As the Republican National Convention kicks off in Tampa, Fla., polls show a tight race between President Obama and challenger Mitt Romney.

A new Washington Post/ABC News poll has Romney at 47 percent and the president at 46 percent -- a virtual dead heat.

But two University of Colorado professors have devised a model that will have delegates buzzing in Tampa.

The model uses economic indicators from all 50 states to forecast the winner.

It shows Romney winning with 320 electoral votes, to President Obama's 218.

The professors say the model has been right in every presidential election since 1980.