The race for the White House has settled on key battleground states, including Florida and Ohio, which were decisive for President Bush in 2000 and 2004, and Michigan and Pennsylvania, won by Democratic presidential candidates Al Gore and John Kerry in 2000 and 2004.
McCain and Obama are also battling in a group of smaller states that could go either way in November, including Virginia, New Mexico, Colorado, Nevada and Iowa. McCain's campaign is targeting Wisconsin and New Hampshire, two states that went for Kerry in 2004.
New CNN/Time/Opinion Research Corp. polls of likely voters found Obama leading 50-47 percent in Wisconsin and 49-47 percent in Ohio. McCain has a slight 48-47 percent edge in North Carolina and 51-45 percent cushion in Indiana. They are tied 48-48 percent in Florida.
David Chalian, ABC News political director, said, "When we tried to nudge some of those battleground states into leaning one way or the other, John McCain is at 227 electoral votes versus Barack Obama's 228, with the remaining 83 electoral votes from eight current toss-up states up for grabs."
The political brawl continued through those states Thursday. Obama stumped in the swing state of New Mexico and has a new ad running on Spanish-language TV, attacking McCain for reversing himself on immigration. The ad accused McCain of "having dos caras [two faces] on immigration."
McCain, accompanied by Palin, held rallies in Iowa and Wisconsin. The Republican launched a new television ad today trying to gin up the Republican base, accusing Obama and his "liberal congressional allies" of wanting to increase government and "billions in spending increases."
Democratic advisers had previously talked optimistically about redrawing the electoral map, even employing Democratic National Committee chairman Howard Dean's "50-state strategy" of putting resources in states that typically vote Republican.
But now Democratic strategists argue that while the race has moved to key battlegrounds, Obama's multistate primary strategy and the DNC 50-state strategy has put new states in play that could get more Democrats elected to Congress and into statehouses in November.
"The 50 state strategy is important to the presidential race, but it's also important down ballot because it's put staff and infrastructure in place in state parties," Woodhouse said, adding, "the messaging, the field work, the door knocking, all of that helps elect Democrats down ballot, whether it be for the Senate or Congress or governors races."
If the presidential campaign remains as tight as it is now, there is also the unlikely possibility of a tied electoral vote 269-269.
If, for example, Obama wins all the states Kerry won in 2004, and picks up Iowa, Nevada and New Mexico, McCain and Obama would each win 269 electoral college votes -- locking the presidential election in a tie.
However, political analysts argue that the underlying trends bode well for Democrats to pick up independent voters, undecideds and Republicans disgruntled with the Bush administration's handling of the war and the economy.
"Obama has a shot at a fairly wide variety of red states, including Nevada, Iowa, New Mexico, Colorado, Ohio, Virginia, North Carolina and Florida -- that's a long list," Sabato said.
"He's not going to carry them all ... but Obama has a very good chance of getting some of the red states," he said, "Will it be enough to get over 270? Let's see how the race unfolds."