Senator Barack Obama has extended his winning streak over Senator Hillary Rodham Clinton, sweeping the so-called Potomac primary in Maryland, Virginia and the District of Columbia. Obama has now won eight straight contests since the nationwide Super Tuesday vote last week. He holds a slight delegate lead going into next week’s primaries in Wisconsin and Hawaii. Two key contests in Texas and Ohio follow early next month. Obama celebrated Tuesday’s win with supporters in Wisconsin.

Sen. Barack Obama: “George Bush won’t be on the ballot this November. George Bush won’t be on the ballot, my cousin Dick Cheney won’t be on the ballot. But the Bush/Cheney war and the Bush/Cheney tax cuts for the wealthy, those will be on the ballot. When I am the nominee, I will offer a clear choice. John McCain won’t be able to say that I ever supported this war in Iraq, because I opposed it from the start.”

Senator Clinton, meanwhile, was in Texas, a key state for her campaign.

Sen. Hillary Clinton: “I see an America where we finally have comprehensive immigration reform with a path to earned legalization. Of course we’re going to have secure borders. We’re going to work very hard on that, and, yes, we’re going to make sure employers don’t exploit undocumented workers. And we will do more to help communities like El Paso that need resources for health and education and law enforcement, and I want to work more with our neighbors and friends to the South to help those countries create more jobs for their own people so that everyone would have a chance at a better life.”

Clinton’s campaign announced another shake-up Tuesday with the resignation of deputy campaign manager Mike Henry. Henry follows Patti Solis Doyle, who stepped down as campaign manager two days before. On the Republican side, Senator John McCain added to his virtually insurmountable lead on Tuesday, defeating main challenger Mike Huckabee in all three states.

Sen. John McCain: “Now, my friends, comes the hard part and for America a much bigger decision. We don’t know yet for certain who will have the honor of being the Democratic Party’s nominee for president, but we know where either of their candidates will lead this country, and we dare not let them. We dare not let them.”

Despite McCain’s wins, polls show he continues to face some opposition from self-described conservatives and evangelicals, losing their vote to Huckabee in Virginia.