Good Tuesday morning. Official opening day brought rain to Yankee Stadium and another 9th inning victory for the Washington Nationals. Our hometown team even won their opener. If yesterday is any indication of how the season's going to go, Politics Nation will be a very happy camper. Here's what Washington is watching today:

-- The Senate meets for morning business before party lunches early this afternoon. After they adjourn, the chamber will take up the House-passed housing bill. With President Bush in the Ukraine, the House will vote on a resolution expressing support for that country and Georgia's entry into NATO. Later, the House takes up a resolution on the 40th anniversary of the assassination of Dr. Martin Luther King, an anniversary coming up on Friday. In Ukraine, President Bush met with President Viktor Yushchenko and his prime minister today, then visited St. Sophia's Cathedral and a local school in Kiev.

-- As recently as last week, key Barack Obama supporters in Pennsylvania were convinced that their candidate wasn't taking the Keystone State seriously. Pennsylvania again offers Obama the chance to knock Hillary Clinton out of the race, as did California, Texas and Ohio. She won each of those, and she leads Pennsylvania by 16 points, per the latest RCP Pennsylvania Average. But with the contest taking place three weeks from today, Obama has the chance to actually compete, and it looks like he's doing so: Later this week he'll finish up a six-day swing through the state, and his campaign has bought 2000 points of advertising in Pittsburgh and Harrisburg and 1700 in Philadelphia, according to Time's Mark Halperin.

-- A little context: 2000 points of television is saturation level. That means the average viewer will see the ad something like 20 times. The ad buy far outpaces Clinton's financial commitment to Keystone television so far. One point in Philadelphia, a source tells Politics Nation, comes out at $535, while a point in Pittsburgh is $235 and a point in Harrisburg is $138. That means Obama is spending about $1.65 million on Pennsylvania television stations this week, just about comparable to pre-Iowa and New Hampshire levels. Lest any backers think Obama is abandoning the state, they may want to reconsider. Then again, it would be better for the campaign's expectations game if they were to appear to take a stronger-than-expected finish. Don't be fooled, Obama wants a Pennsylvania win.

-- He wants the win so much he's even changing the way he talks, the New York Times' Michael Powell writes today. Traveling with Pennsylvania Senator Bob Casey, whose family ties to blue collar workers go back a generation, Obama is talking about corporate profiteers to crowds who are watching their jobs disappear. Bowling and chowing down on a hot dog alongside Casey in State College, Obama's even starting to look the part, less a professor than a candidate who feels working class pain, as the Baltimore Sun writes.

-- The message from Johnstown yesterday and State College this weekend sounded more John Edwards than Barack Obama, and perhaps the goal is two-fold: First, woo the middle income families whose jobs are going overseas and who would be predisposed to vote for Clinton. If Obama scores a win in Pennsylvania, the Democratic race is over. If not, he'll wait a while longer to be coronated as the Democratic nominee. The second goal may be to make an inroad or two with Edwards heading into the North Carolina primary, where an endorsement could again lock away the nomination. Job number one on that front: Repair relations with Elizabeth.

-- But if the race continues, make no mistake that Clinton has a shot. That's because she could end up with a popular vote majority while Obama leads among delegates, US News' Michael Barone writes. To play by the rules, Obama would still have an advantage going into the convention, but leading among all voters is a compelling reason for Clinton to stay in the race. If the contest goes to Denver, her chances depend less on the candidate herself than on enforcers like Harold Ickes and James Carville, two veterans who know their way around a deal and have plenty of chits to call in. Ickes has been cutting super delegate deals already, while Carville's op-ed slamming Bill Richardson was a marker for any other super delegate who owes the Clintons.

-- Meanwhile, John McCain continues his biography tour today with a stop at his old high school in Alexandria, just across the river from Washington. McCain will describe himself as a "rambunctious" kid who flaunted the rules. Tomorrow he heads to his alma mater, the Naval Academy in Annapolis, Maryland. And he's seriously up on television, as well: That ad we told you about recently will be running in New Mexico at about 750 points a week, Jonathan Martin writes, coming to a two-week total of $250,000.

-- McCain is running the same ad in Spanish, CBS' Dante Higgins reports. It's the first time his campaign has run a Spanish-language ad, and Republican strategists around the nation's capitol have to be breathing a sigh of relief. McCain's more moderate stance on immigration could help slow, if not stem, the tide of Hispanic voters abandoning the GOP, an epidemic the party is facing more urgently in recent years. On the other hand, what does it say to conservative activists, especially anti-immigration hardliners, that McCain is willing to spend campaign money on Spanish language advertisements right in the middle of the "conversation" that was supposed to bring Republican voters firmly back into the fold?

-- Guest Of The Day: Hillary Clinton will appear on Jay Leno's Tonight Show Thursday, the third time she's appeared on the comedian's couch, as NBC's First Read reports. More immediately, John McCain will take a break from his biography tour to sit down with his favorite late night host, David Letterman, for air this evening. Remember the number one rule, politicians: Don't be the funny guy! They pay the guy sitting next to you millions to fill that role.

-- Today On The Trail: Clinton tours a company and addresses the state AFL-CIO in Philadelphia before hitting a town hall meeting in Wilkes-Barre and rallying in Erie. Obama swings through town hall meetings in Wilkes-Barre and Scranton, Bob Casey's home base. McCain visits his old high school in Alexandria before sitting down with Letterman.