History's tingle must have been felt by many Americans as they watched Sen. Barack Obama accept the Democratic Party's nomination in Denver on Thursday night.

Forty-five years ago this week, 100,000 people marched on Washington to demand that African-Americans be treated as full and equal citizens under the law. Obama's achievement as the first African-American major-party presidential nominee is a marker of how far America has moved toward fulfilling the dream of racial justice that Martin Luther King Jr. set before the nation. The coincidence of Obama accepting the nomination on the anniversary of King's famous oration guaranteed the Democrats an emotion-packed, rollicking night, no matter where they set up their tent. They pitched it in a place where 76,000 people could attend, Denver's Invesco Field.

The choice was fitting for a candidate who emphasizes the power of ordinary people to change America. But the big venue also became fodder for GOP shots about Obama's alleged cultivation of celebrity status. It's an odd line of attack. Seldom has a politician come under fire for his ability to draw a crowd. Republican candidate Sen. John McCain refused to sully himself with such pettiness yesterday. He released a classy personal ad congratulating Obama -- though his surrogates, including Minnesota Gov. Tim Pawlenty, continued to pepper the Democratic nominee with the charge that his record is too skimpy for the presidency.

Obama's acceptance speech should go some distance in addressing such doubts. He described well the problems of average Americans -- rising unemployment and underemployment, eroding housing values, and mounting debt loads, energy prices and college tuition. He rightly acknowledged that government was not the source of all those difficulties, and he emphasized personal responsibility. But he rightly tagged both President Bush and "broken politics in Washington" for an inadequate federal response.

He described how he would respond, going well beyond perfunctory slogans about change. Obama spoke of tax incentives for companies that create jobs in this country rather than abroad, tax breaks for small businesses and high-technology startups, and a middle-class tax cut big enough to reach 95 percent of working families.

He also vowed to set a bold goal reminiscent of John F. Kennedy's moon challenge: "In 10 years, we will finally end our dependence on oil from the Middle East." He accurately described offshore drilling for oil, the silver-bullet fixation of this summer's campaign, as "a stopgap measure, not a long-term solution."

Left unmentioned was one aspect of Obama's tax proposals -- allowing at least a portion of the Bush tax cuts to expire for the nation's top earners. As the campaign progresses, the Democratic nominee will need to answer the charge that even a tax increase confined to those who have gained much in this decade will knock an already faltering economy to its knees.

"America, we are better than these last eight years," Obama assured an anxious nation last night. Legions of Americans agree. They want to vote for a presidential candidate who knows the way to a better America, and who has the ability to lead the nation there. With a history-charged, forward-looking convention, Obama advanced his case that he can be that president. McCain's counterargument is next up, and, luckily, Minnesotans will have a ringside seat.