Republican John McCain's recent surge in opinion polls has restored a familiar look to a White House race that once promised to reshuffle the political map, with traditional battleground states like Ohio and Michigan back at centrestage.
Mr McCain's momentum has improved his standing in several swing states that hold the keys to the White House, and put a dent in Democrat Barack Obama's hopes of expanding the fight to normally Republican states like Georgia, Montana and Indiana.
As a result, the November 4 presidential election is likely to be decided in many of the same states as the 2004 race between Republican President George W. Bush and Democratic challenger John Kerry.
Four big battleground states - Ohio and Florida, won by Mr Bush in 2004, and Pennsylvania and Michigan, won by Mr Kerry - will be top targets for Mr Obama and Mr McCain in the next seven weeks.
New Hampshire, Virginia and three toss-up states in the West - Nevada, Colorado and New Mexico - also will get plenty of attention from the candidates. All but New Hampshire were won by Mr Bush in 2004, and only Virginia and Colorado were not hard-fought in that race.
Other states like Wisconsin, Minnesota and Missouri could rise to prominence in the next seven weeks as the candidates hunt for the 270 electoral votes needed to win the White House. Those votes, allocated to each state based on their population, are awarded to the popular-vote winner in each state.
The momentum generated by Mr McCain with his pick of Alaska Gov. Sarah Palin as his No. 2 has propelled him into essentially a tie with Mr Obama in national polls.
At the state level, it allowed Mr McCain to close the gap on Mr Obama in Democratic-leaning Michigan and Pennsylvania - states where a McCain win would spell disaster for Mr Obama -and to open solid leads on Mr Obama in states like Florida and Missouri.
Mr McCain has a slight lead in Ohio, which could prove to be the ultimate battleground again just as in 2004, when Mr Bush's narrow win there edged out Mr Kerry.
"McCain probably can't win without Ohio, it gets very hard to piece together the electoral votes he needs without it," said Peter Brown, assistant director of the Quinnipiac Poll. "Obama can't win without Pennsylvania."
Mr Obama had hoped a national surge in Democratic voter registration, along with record turnout among young and black voters, could help boost him in traditional Republican strongholds like Georgia, North Dakota, Montana and Indiana, but those hopes appear to be fading.
Mr Obama, an Illinois senator, still has a strong shot at capturing several states won by Mr Bush in 2004. At the top of the list is Iowa, where Mr Obama started his run to the Democratic nomination with a win in January and where Mr McCain finished a weak fourth among Republicans.
Mr Obama and Mr McCain also are running neck-and-neck in New Mexico, Colorado and Nevada, three states where population changes and a growing Hispanic electorate have bolstered Democratic prospects.
Mr Obama, who would be the first black US President, also hopes to capture Virginia, a Southern state that has not voted for a Democrat in a presidential race since 1964. The state has shifted toward Democrats in recent elections as the growing northern suburbs outside Washington account for one-third of state voters. Mr McCain has solidified his lead in the past few weeks, but Mr Obama has made a major push for the state's 13 electoral votes.
Mr Obama, however, has struggled in Florida to keep pace with the showings of Mr Kerry, who lost by five percentage points, and Mr Gore, who lost the state to Mr Bush by 537 votes in a disputed result in 2000.