Clinton suffered another wave of dispiriting losses against Sen. Barack Obama. He beat her in Virginia 64 to 35 percent, in Maryland 61 to 35 percent and in the District of Columbia 75 to 24 percent, according to incomplete returns. These trouncings give Obama a perfect 8-0 record against Clinton in the primaries and caucuses held since Super Tuesday. He walks away with most of the 171 delegates that were at stake in the Potomac Primary and moves on to next Tuesday’s contests–Wisconsin and Hawaii–with a fresh jolt of momentum. He has also ratcheted up the pressure on Clinton to win on March 4 in Ohio and Texas–two states her campaign has repeatedly described as bulwarks. “At this moment, the cynics can no longer say that our hope is false,” Obama said at a rally in Madison, Wis., on Tuesday night. “We have now won East and West, North and South and across the heartland of this country that we love.” (Clinton declined even to mention the night’s results at an event in El Paso, Texas.)

Obama found plenty to celebrate in Tuesday’s exit polls. In Virginia–the most closely watched and contested of Tuesday’s competitions–it was no surprise that he trounced Clinton among blacks and young voters. What was surprising, and surely worrisome to the Clinton campaign, was that Obama beat her among women, 58 to 42 percent, and pulled nearly even with her among whites, garnering 48 percent compared to her 51. He also defeated her in two other categories that she has usually dominated: lower-income groups and people without a college degree. All of which shows that Obama succeeded in broadening his coalition. (His performance might also serve as a riposte to statements like those from Pennsylvania Gov. Ed Rendell, a Clinton supporter, who told the Pittsburgh Post-Gazette editorial board last week that some conservative whites in his state “are probably not ready to vote for an African-American candidate.”)

Clinton’s losses cap a tough run for her campaign. She drew a week of gloomy news coverage stemming from the disclosure that she was forced to loan her campaign $5 million and from the replacement of her campaign manager (on Tuesday, her deputy campaign manager resigned as well). The campaign now confronts naysaying “national media chatter” and “nervous supporters,” says one adviser, who declined to be named discussing internal matters. As a result, Clinton has been phoning backers and superdelegates to reassure them that her campaign is righting itself. “She’s trying to keep their eye on the ball, which is the long march to delegates,” says the adviser. A memo released on Monday by Mark Penn, Clinton’s chief strategist, sought to switch the focus of the discussion to Clinton’s supposed strength as a candidate against Sen. John McCain in the general election. Among his arguments: that Clinton is battle-tested against the Republican attack machine, and that she can beat him in a debate on national security.

Yet Clinton faces challenging contests next Tuesday in Hawaii and Wisconsin. Obama spent part of his youth in Hawaii and is regarded as a native son. Wisconsin bears some of the characteristics that have helped him win in other states: large pockets of students and an open primary that allows independents to vote. No surprise, then, that Obama headed straight to the university town of Madison on Tuesday night. By contrast, Clinton set off for Texas, where she was scheduled to hold events on Wednesday in McAllen, Robstown and San Antonio–all cities rich with Hispanic voters, who have generally served as a dependable firewall for her this nominating season. From there, she plans to head up to Ohio, where her campaign believes that her economic message will resonate with a large population of working-class voters.

The battle for the Latino vote in Texas will be especially hard-fought. Hispanics make up about 25 percent of eligible voters in the state, and could account for as much as half of those turning out in the Democratic primary. Hoping to tap that potential gold mine of support, Clinton is running Spanish-language ads and deploying a contingent of Hispanic heavy-hitters, including Rep. Silvestre Reyes and Henry Cisneros, the former mayor of San Antonio and a cabinet member in President Bill Clinton’s administration. For his part, Obama, who was late in mounting an aggressive Latino outreach effort, is hoping to eat into Clinton’s Hispanic base with his own ads and surrogates. On Tuesday night, he demonstrated that he’s capable of doing so: according to exit polls, he won the Hispanic vote in Virginia.

On the Republican side, Sen. John McCain swept the contests, further solidifying his position as his party’s presumptive nominee. He defeated former Arkansas governor Mike Huckabee in Virginia 50 to 41 percent, in Maryland 55 to 30 percent and in the District of Columbia 68 to 17 percent, according to incomplete returns. Still, McCain suffered a scare in Virginia. Earlier in the day, his aides huddled at headquarters to analyze exit polls. They showed that while McCain did well among moderate Republicans, Huckabee captured 70 percent of voters who described themselves as “very conservative” and narrowly led him among independents, a key McCain demographic. In the end, aides credited the senator’s victory to his strength in northern Virginia, the most populous (and a more moderate) area of the state.

Greeting supporters in Alexandria, Va., on Tuesday night, McCain commended Huckabee as a “formidable campaigner.” “He certainly keeps things interesting–a little too interesting at times tonight, I must confess,” McCain said. Yet as the nomination has increasingly neared his grasp, he has turned his attention to other matters: assembling a general election campaign, raising money and cultivating support. While close aides and surrogates have been reaching out to conservative activists and talk radio personalities who have criticized his campaign, he’s been courting members of Congress. On Tuesday, McCain spoke before a weekly Senate Republican luncheon, where he spoke of his desire to unite the party and help Republicans win back majority control of Congress, according to a GOP aide who was not authorized to speak on the record.

The biggest unknown: how much pressure the McCain campaign will put on Huckabee to end his increasingly quixotic quest. Already, supporters of the senator, like Texas Gov. Rick Perry, have called for Huckabee to drop out for the good of the party. But on Tuesday night, Huckabee declared, “We march on. … The nomination is not secured” until someone captures the 1,191 GOP delegates needed to win. McCain doesn’t seem all that concerned. In his victory speech, he mostly aimed his comments at Democrats, including some that seemed to single out Obama. “Hope, my friends is a powerful thing,” he said. “I can attest to that better than many. … [But] to encourage a country with only rhetoric rather than sound and proven ideas that trust in the strength and courage of free people is not a promise of hope. It is a platitude.” Though the Democratic nominating contest remains unsettled, it seems like one candidate in particular is on his mind.