And now the main event . . .

by Christi Parsons

ST. PAUL--New characters are onstage. Scripts have been revised with a fall audience in mind.

And now that the back-to-back political conventions are over, the longest-running presidential campaign in memory enters its home stretch--finally--with the promise of new drama.

The dynamics are notably different today from just a couple of weeks ago, when Republican John McCain and Democrat Barack Obama were still only their parties' presumptive nominees.

Gov. Sarah Palin as McCain's running mate changes the story line significantly, a decided curve for a Democratic team unprepared for the hockey-mom-as-attack-dog scenario.

McCain is signaling a shift in his "we're more experienced" theme by naming a vice presidential candidate who still features the PTA on her résumé.

And there's no accounting for how Democrat Joe Biden could shake things up as Obama's recently added sidekick, a smart and quirky character with as much propensity to upstage as to stick his foot in his mouth.

With two months, four debates (one of them pitting Palin against Biden) and miles to go before its conclusion, the real show starts today.

Read the full story in today's Tribune.