Good Monday morning. President Bush threw out a pretty good first pitch yesterday (albeit a little high) as Ryan Zimmerman, with his bottom of the 9th home run to win the Nationals' opening game in their new park, took over the title of Washington's most respected person. Here's the rest of what Washington is watching today:

-- Like the swallows to Capistrano, Congress finally returns to session this morning after a two-week recess. The Senate will conduct morning business most of the day, while the House considers a number of land transfers, park expansions and species-conservation efforts and the creation of the National Integrated Coastal and Ocean Observation System. President Bush is headed to the Ukraine this morning for a meeting of NATO allies. Later today, Vice President Cheney holds a fundraiser for State Senator Brett Guthrie, who is running to replace retiring Rep. Ron Lewis in Kentucky's Second District.

-- Treasury Secretary Henry Paulsen will announce what experts call the most sweeping overhaul of regulation on the American banking and trading industry since Franklin Roosevelt came to power after the Great Depression. New federal regulators with power over every facet of Wall Street will begin to check some investment entities that operate largely above regulation now, and the Federal Reserve will have new powers to help institutions limit risk, a notion that has some conservatives up in arms. In fact, the New York Times writes, the new plan comes a year after Paulsen began looking for new ways to unburden Wall Street of regulations. The financial crisis isn't going away, putting more pressure on the presidential candidates to come up with a solution.

-- On the White House trail, following Pennsylvania Senator Bob Casey's somewhat surprising announcement that he would back Barack Obama after remaining neutral for so long, Minnesota Senator Amy Klobuchar, like Casey a freshman elected in 2006, will back Obama today, the Wall Street Journal's Jackie Calmes writes, while all seven of the North Carolina Democratic delegation are likely to throw their support behind Obama before the May 6 primary. Rep. David Price, speaking on Politics Nation radio this weekend, hinted that he was at least leaning in that direction -- his largely urban district also includes the state's "research triangle," which is home to several Obama-loving colleges. Obama's inching up on Hillary Clinton in terms of super delegates, trailing by only a few dozen. Those super delegates are her only chance of winning the nomination. Could Clinton's exit be closer than we think?

-- Not if the candidate's statements are to be believed. "I have no intention of stopping until we finish what we started and until we see what happens in the next 10 contests and until we resolve Florida and Michigan. And if we don't resolve it, we'll resolve it at the convention -- that's what credentials committees are for," Clinton told the Washington Post in a story that led Sunday's paper. As polls show the race widening in favor of Obama, and as super delegates keep heading in the Illinois Senator's direction, Clinton said she did not envision a scenario in which she does not take the contest to the convention. Obama's response: "My attitude is that Senator Clinton can run as long as she wants," he said Saturday during a stop in Pennsylvania.

-- The central argument between Clinton and Obama: Whether Clinton's victories in Ohio, California, Nevada and other states, along with her big lead in Pennsylvania, translate into her ability to actually carry those swing states in November, or whether Obama's victories in more marginal swing states mean he can expand the map, as the Washington Times' Christina Bellantoni writes. Clinton's campaign is warning super delegates that Obama will not be able to win the states necessary to capture enough electoral votes, while Obama's campaign is promising an expanded Democratic map that includes states Clinton has already written off, like North Carolina, Virginia and Missouri.

-- While Democrats continue to squabble, John McCain will begin a nationwide biography tour this morning, spending a week on the trail in places like Mississippi, Annapolis and Alexandria, Virginia, where he went to high school. But as the war in Iraq gets more violent, how far can McCain's focus on his record as a war hero actually go? He's so closely associated with the military, some say, that his own biography could make voters question his willingness to use force. "The question is whether he can convince people that he will not only keep us safe but also be cautious in using military power," former presidential adviser David Gergen told Bloomberg's Edwin Chen.

-- But, contrary to conventional wisdom, with an unpopular war and economic woes sustained under a fellow Republican, McCain is still polling even with Clinton and Obama, the Associated Press notices. McCain polls better against Clinton than against Obama in the latest RCP National Averages, but Clinton, perhaps validating her argument, does better against the Republican in RCP Pennsylvania, Ohio and Florida averages.

-- But how is McCain staying on top? It's one or a combination of three reasons: The most obvious is squabbling withing the Democratic Party; when given a choice between the Democrat they do not support in the primary and McCain, some voters are saying it's their way or the highway. That's bad for McCain: Eventually, those Democratic wounds will heal. Reason 2: The idea of McCain as straight-talker who, despite his party affiliation, is still anathema to President Bush, is still sewed into the minds of voters. That's great for McCain: It will take a lot more money to dislodge an 8-year-old opinion this year than a new one. Reason 3: In a time of war and uncertainty, the veteran with more experience is the candidate voters want. That's a mixed bag: It means McCain depends on the war in Iraq staying bad enough to be in the headlines ahead of the economy (which he won't do) and basing his whole campaign on experience (an issue on which he has a clear advantage but which Clinton couldn't convert to a win in the primary).

-- Administration Woe Of The Day: As President Bush heads to the Ukraine, he's going to need to begin contemplating a new nominee for the Department of Housing and Urban Development. Embroiled in a controversy over whether he steered contracts to friends, HUD Secretary Alphonso Jackson will resign today, the Wall Street Journal reports. The move came just a week after two prominent Democratic Senators with leverage over the beleaguered department called on Jackson to resign, given the allegations of wrongdoing and his poor relationship with the new majority party.

-- Today On The Trail: McCain launches his biography tour in Meridian, Mississippi with a speech at Mississippi State University. Obama's Pennsylvania bus tour is continuing, and lands today in Lancaster for a town hall meeting and Allentown for a rally. Clinton has a roundtable set up in Harrisburg before rallying in Fairless Hills, while husband Bill Clinton holds events across Oregon today.