Mitt Romney will win. The tie in the polls goes to the challenger. Here’s why:

Enthusiasm. It matters enormously, and it’s disproportionately on the Republican side, in good measure because of an intense desire to defeat President Obama. True, enthusiasm doesn’t guarantee an edge in turnout, but it’s certainly a key indicator. “In these final days, turnout is driven by intensity,” says Republican pollster Ed Goeas.  The nearly half the electorate that strongly disapproves of Obama’s performance in office “will need little else other than the opportunity to vote against President Obama to motivate them to go to their polling place.” Goeas conducts the bipartisan Battleground Poll along with Democrat Celinda Lake.