Democratic Sen. Barack Obama and Republican Sen. John McCain battled for the White House on Tuesday in an election that challenged attitudes about race as surely as it gauged sentiments about the battered economy and the war in Iraq.

As if unwilling to cede the stage, both men campaigned into Election Day. Obama, bidding to become the first black president, greeted voters in Indiana. McCain held rallies in Colorado and New Mexico.

The White House was the main prize of the night on which 35 Senate seats and all 435 House seats were at stake. In both cases, Democrats hoped to pad their existing majorities, and Republicans braced for losses.

A dozen states elected governors, and ballots across the country were dotted with state legislative races and ballot questions on issues ranging from taxes to gay rights.

By tradition, the first handful of ballots were cast just after midnight in tiny Dixville Notch, N.H. Obama got 15 votes and McCain six.

They were the first of tens of millions in the race to gain 270 electoral votes and succeed George W. Bush on Jan. 20 as the 44th president.

An estimated 153 million voters were eligible, and in an indication of interest in the battle for the White House, 40 million of so had already voted as Election Day dawned. Turnout was heavy. In Virginia, for example, officials estimated nearly 75 percent of eligible voters would cast ballots.

Obama awaited the results at home in Chicago after a marathon campaign across 21 months and 49 states. At 47, with only four years in the Senate, he sought election as one of the youngest presidents, and one of the least experienced in national political affairs.

That wasn’t what set the Illinois senator apart, though — neither from his rivals nor from the 43 men who have served as president since the nation’s founding more than two centuries ago. A black man, he confronted a previously unbreakable barrier as he campaigned on twin themes of change and hope in uncertain times.

McCain, a prisoner of war during Vietnam, a generation older than his rival at 72, waited in Arizona to learn the outcome of the election. It was his second try for the White House, following his defeat in the battle for the GOP nomination in 2000.

A conservative, he ran seeking to stress his maverick’s streak. And a Republican, he did what he could to separate himself from an unpopular President Bush.

For the most part, the two presidential candidates and their running mates, Republican Gov. Sarah Palin of Alaska and Democratic Sen. Joe Biden of Delaware, spent weeks campaigning in states that went for Bush four years ago. Virginia, Florida, North Carolina, Ohio, Iowa, Colorado, New Mexico and Nevada drew most of their time. Pennsylvania also drew attention as McCain sought to invade traditionally Democratic turf.

McCain and Obama each won contested nominations — the Democrat outdistancing former first lady Hillary Rodham Clinton — and promptly set out to claim the mantle of change.

“I am not George W. Bush,” McCain said in one debate.

Obama retorted that he might as well be, telling audiences in state after state that the Republican had voted with the president 90 percent of the time across eight years of the Bush administration.

After voting with her husband, the former president, Clinton called Bush “the lamest of lame ducks” and predicted that Obama would begin making presidential appointments and announcing economic policies within weeks.

The war in Iraq dominated the campaign early in the year, but by Election Day it had long since faded as an issue.

The economy mattered above all else, with millions facing foreclosures on their homes, joblessness rising and Americans tallying the losses in their retirement accounts after a stock market plunge.

The race was easily the costliest in history, in excess of $1 billion, more after the congressional campaigns were counted.

McCain accepted federal matching funds, and was limited to $84 million for the fall campaign.

After first saying he would go along, Obama reversed course, then raised and spent multiples of what his rival was allowed.

McCain sought to make an issue of that, saying Obama had broken his word to the public. At the same time, for weeks on end, he could not match his rival’s television advertising onslaught.

Figures through mid-October showed Obama had spent roughly $240 million on television and radio advertisements.

McCain had shelled out about $115 million, and the Republican National Committee another $80 on his behalf.

In the battle for Congress, Democrats began the night with a 51-49 majority in the Senate, including two independents. Their majority in the House was 235-199, with one vacancy.

In both cases, Republicans fought to overcome a financial disadvantage as well as numerous retirements.

The governor’s races included open seats in North Carolina, Delaware and Missouri.

The ballot issues ran from a measure to ban abortion in South Dakota to proposals outlawing affirmative action in Colorado and Nebraska. Three states voted on gay marriage.