BOCA RATON, Fla. (AP) — President Barack Obama and Republican Mitt Romney are opening a two-week sprint to Election Day powered by adrenaline, a boatload of campaign cash and a determination to reach Nov. 6 with no would-have, should-have regrets.

The candidates will vastly accelerate their travel, ad spending and grass-roots mobilizing in a race that's likely to cost upward of $2 billion by the time it all ends.

All the focus now is on locking down support in the nine states whose electoral votes are still considered up for grabs. Obama campaigns Tuesday in Florida and Ohio while Romney heads west to Nevada and Colorado.

Neither candidate scored a knockout punch in their third and last debate Monday, as both men reined in the confrontational sniping that had marked their last testy encounter.