The presidential contest is being fought largely on what has been Republican turf, with Obama leading or running even in such states as Ohio, Virginia and Colorado.

If that continues, it should work to Obama's advantage, although McCain hopes to thwart his rival by removing Michigan and Pennsylvania from the Democratic column.

The tilt of the race is evident in looking at the toss-up states. According to the nonpartisan Web site RealClearPolitics.com, there are 11. And just two - Michigan and New Hampshire - went for John Kerry in 2004.

The rest were Bush states, including such longtime GOP strongholds as Indiana and North Carolina.

David Plouffe, Obama's campaign manager, looks at the map and sees "a huge range of possibilities to get to 270," the winning number of electoral votes. He has told reporters that he was "simply not going to wake up on [Election Day] worried about one state."

A confident Obama spent last week in states that President Bush took twice: Missouri, Ohio, Colorado, North Dakota and Montana.

If Obama wins everywhere the Democrats won four years ago, he'll have 252 electoral votes and could go over the top by taking Ohio or Florida or a combination of smaller states in the West, South and Midwest.

As for McCain, unless he can make inroads into Democratic turf, he'll spend the autumn playing defense, trying to hold off Obama in the red states.

In the view of Republican strategists, McCain's distinctive political profile and Obama's relative weakness with working-class whites give the Arizona senator a shot at Michigan and Pennsylvania, both of which have gone Democratic four times in a row.

"No doubt the environment is very challenging for Republicans by just about every measure," said Michael DuHaime, senior adviser for political operations at the Republican National Committee. "Given that, it's encouraging that we have a candidate with the ability to bring in independents, moderate Republicans and swing Democrats."

A lot can change between now and Nov. 4. Still to come are the vice presidential selections, the conventions, the debates, and changes in the price of oil, the economy, and the war in Iraq.

"If the national race is mid- to high single digits for Obama, as it seems right now, it'll be an Electoral College blowout or close to it," said Peter Brown, analyst for the Quinnipiac University Polling Institute, which surveys swing states. "But if it narrows, the electoral geography gets much more interesting."

Here's the current Electoral College outlook.

Midwest. For both campaigns, no region looms larger. Two states, Ohio and Michigan, figure to be key.

No Republican has won the presidency without Ohio. Ever. If Obama can take it this year - and he did not do well in the Ohio primary - it's hard to see how McCain can win the White House. Some polls have the Illinois senator ahead there now.

Then there's Michigan, home to the original "Reagan Democrats." Of all the big states Kerry captured in 2004, it looks to be the most promising for McCain now.

Obama was hurt there by the dispute over party rules that led him to skip the Michigan primary. It's a must-win; he has a slim lead in the polls.

In pursuit of his hopes of expanding the playing field, Obama has designs on two unlikely Midwestern targets.

One is Indiana, which has voted Democratic only once since 1936; the polls are even there. Another is North Dakota, which Obama won big in the caucuses. He's running television commercials in both states.

Obama seems comfortably ahead in Wisconsin and Minnesota; both were battlegrounds in recent elections, going narrowly Democratic.

He also has strong prospects in Iowa, the state that propelled him to his party's nomination. It is the 2004 Republican state most likely to turn Democratic in 2008.

West. Both campaigns have targeted Nevada, New Mexico and Colorado, mountain-state battlegrounds in the last two presidential elections.

These three states have just 19 electoral votes among them, but they figure to be crucial in a tight race. Kerry would be president if he had carried them four years ago; he lost all three by a total of 127,011 votes.

Said analyst Brown: "To me, these states, plus Iowa, provide the most plausible path to victory for Obama."

Bush drew 40 percent of the Hispanic vote nationally four years ago. That and his success among rural white voters allowed him to carry the three states.

McCain's strategists believe that his years of dealing with Western issues, plus his familiarity with Latino concerns and his support for legalizing many undocumented immigrants, should help in the states, all of them adjacent to Arizona.

Obama is favored in California, Oregon and Washington. McCain should win Idaho, Utah and Wyoming.

Obama's campaign, though, believes it has an opening in Montana, where he spent the Fourth. The state has a moderate Democratic governor and elected its second Democratic senator, Jon Tester, two years ago.

Northeast. Every state in the region voted Democratic in 2004, and a repeat is not out of the question. At this point, only two states seem in play.

One is New Hampshire. Even though it has only four electoral votes, Obama thought enough of its importance to let it host his big unity appearance with Hillary Rodham Clinton.

New Hampshire has become more Democratic since voting for Kerry four years ago. But it also happens to be McCain's second political home; this year, he staked his candidacy on winning its Republican primary. He won the 2000 primary as well.

The other battleground is Pennsylvania, which has seen both McCain and Obama twice in the last few weeks.

In Pennsylvania, McCain can take heart from the closeness of the Kerry-Bush race in 2004 and the thumping Obama received in the primary this spring.

Obama ran poorly in the culturally conservative western counties - where a Democrat needs to hold his own in the fall - and not as well as he had hoped in the Philadelphia suburbs. McCain will target both areas; he knows that it's hard for a Democrat to get to 270 without Pennsylvania.

Statewide polls give Obama the lead despite the damage he inflicted on himself by describing small-town Pennsylvanians as "bitter."

McCain also is promising an effort in New Jersey. Analysts wonder how much time and money he'll invest on a state that has been solidly Democratic in recent years.

South. The question here has to do with demographics. Can Obama, an African American, break the Republicans' lock on a region that is home to half the nation's black residents?

In the last two elections, Democrats have failed to carry a single Southern state. But Obama is within range of McCain in at least three: Florida, North Carolina and Virginia. Plouffe, Obama's campaign manager, has expressed high hopes for Georgia, too.

Obama aims to boost black voter registration and turnout throughout the region. By some estimates, Georgia alone has 600,000 eligible but unregistered black voters. And he has some appeal to younger, better-educated Southern whites.

But it will take more than that for him to win in the South. Thomas Schaller, a scholar of Southern politics, argues that the region's white vote will act as a "formidable counterbalance" to an energized black vote.

"The more blacks there are in a Southern state, the more likely the white voters are to vote Republican," Schaller, a professor at the University of Maryland-Baltimore County, wrote in a New York Times op-ed piece last week.

That, he wrote, helps explain why Mississippi, with the nation's largest black population in percentage terms, is one of the most solidly Republican states.

Virginia, with its growing and affluent Washington suburbs, is where McCain might be most vulnerable. The state has elected two straight Democratic governors and is expected to send a second Democrat to the Senate this year.

"Looking at the rest of the South, it would take a pretty seismic shift for any of those states to flip," said DuHaime, the Republican strategist. "They were double-digit wins for President Bush [in 2004] and are all trending Republican at the state level."

INSIDE

The electoral maps: 2004 vs. 2008. A16.

"Frenzy" over his Iraq remarks baffles Obama. A16.

Currents

Who will win the Republican veepstakes? Dick Polman, C1.

McCain's asset: Integrity. Kevin Ferris, C1.

Pakistan is make-or-break issue. Michael Smerconish, C5.

Obama's plan for faith-based initiatives. Editorial, C4.