Insight - Could Obama's "ground game" clinch the election?

U.S. President Barack Obama speaks at a dinner with winners of a campaign contest at the Smith Commons restaurant in Washington October 12, 2012. REUTERS/Yuri Gripas

CLEVELAND/MIAMI (Reuters) - From the outside, it looked like an abandoned storefront in a run-down part of Cleveland. But inside, dozens of supporters of President Barack Obama gathered on a recent Sunday for an event that was part political rally, part religious revival.

"Gotta vote" signs hung from the ceiling and smoke from an outside grill wafted through the room. Hot dogs, buns, chips and sugar cookies were laid out on a table for the volunteers, most of whom were African-American.