Sneak Peek: This is bowling. There are rules.

Both Democratic candidates continued campaigning in the Keystone State Tuesday.

April 01, 2008— -- Over the course of this long campaign, Hillary Clinton has on a few occasions reminded the reporters trailing her that she does indeed have a sense of humor.

So perhaps it was not surprising that when Clinton began to speak in a serious, somber tone in Philadelphia about the tight Democratic race and a way to bring an end to things, a buzz went through the press corps:

"Was she dropping out? Formally inviting Senator Obama to a joint ticket? But when Clinton began tweaking Obama's efforts this weekend to woo the votes of Pennsylvania's 10-pin playing Demcorats, they knew the joke was on them," ABC News' Eloise Harper reports.

"I want to take a moment to say that this has been a very hard fought race. Each of us is drawing enormous support we clearly need to do something so our party and people can make the right decision," Clinton began.

(Wait for it…)

"So I have a proposal today. I am challenging Senator Obama to a bowl-off. A bowling night. Right here in Pennsylvania. Winner take all. I'll even spot him two frames. It's time for his campaign to get out of the gutter and allow all of the pins to be counted."

"I am prepared to play this game all the way until the 10th frame. When this game is over the American people will know when that phone rings at 3am they will have a president who is ready to bowl on day one." LINK

Zing!

The Clinton traveling press corps cannot be faulted for falling for the April Fools Day joke, given the high tension and heated rhetoric on the campaign trail these days. (And the fact that most of the reporters probably haven't had a day off in months, so who looks at a calendar?)

Considering Obama's performance over the weekend at a bowling alley in Altoona PA (a cringe-worthy 37 with a few gutter balls), he better hope that the idea of a bowl-off for the nomination doesn't catch on among party leaders.

Bowling may be the most absurd way to settle this nomination but beyond Just Wait It Out and Let the Primaries End, no proposal on what to do with the uncommitted superdelegates has garnered much enthusiasm or consensus.

ABC News' Z. Byron Wolf reports that Senate Majority Leader and uncommitted superdelegate Harry Reid said today that he supports a plan to have superdelegates make their preference public by July 1, well before the convention in Denver.

"I like that — July 1 or before," Reid said in a hallway off of the Senate floor.

DNC Chairman Howard Dean is not keen on the idea of a superdelegate convention, which is being floated by Tennessee Gov. Phil Bredesen. In an interview with USA Today, Dr. Dean said a convention of superdelegates cannot happy because "it would look like 330 delegates are overriding the wishes of 30 million voters."

John McCain continues his biography tour tomorrow with a stop in Annapolis to highlight his years at the U.S. Naval Academy.

The theme of McCain's remarks will be service to America, which is not surprisingly given the venue of Navy-Marine Corps Memorial Corps Stadium and backdrop of the Academy's campus. McCain will talk about the importance of service to the country and reflect on his time at the Naval Academy (perhaps a shout out to those toiling at the bottom of the class, like he did?)

ABC News' Sunlen Miller reports that Obama said today that while McCain's biography "is worthy of admiration," his argument with the Republican is his policies.

And batten down the hatches, Teresa Heinz Kerry is back on the campaign trail. The wife of presidential candidate John Kerry was frequently good for a quirky story or headline in 2004, from her Mama T's brownies on the plane to her frequent commenting on how beautiful she found her husband's running mate, John Edwards.

The almost-First Lady takes the stage with Michelle Obama in friendly territory Wednesday with a rally in Pittsburgh. The Heinz name, of course, carries significant weight in western Pennsylvania – and adorns ketchup bottles and a football stadium – and the Obama campaign could use the boost in those western counties as they try to close the margin in the Keystone State.

On the campaign trail. . .

BARACK OBAMA

-- Attends 38th Pennsylvania AFL-CIO Constitutional Convention, Philadelphia, PA

-- 12:20 pm ET: Attends town hall meeting with voters, Wallingford, PA

-- 5:00 pm ET: Appears on the MSNBC Hardball College Tour

MICHELLE OBAMA

-- 2:15 pm ET: Attends rally with Teresa Heinz Kerry and voters, Pittsburgh, PA

HILLARY CLINTON

-- 11:00 am ET: Hosts an economic summit, Pittsburgh, PA

-- Holds policy briefing with campaign policy advisers via telephone

BILL CLINTON

-- 9:00 am ET: Attends event with voters, Columbus, IN

-- 10:45 am ET: Attends event with voters, Seymour, IN

-- 12:30 pm ET: Attends event with voters, Bedford, IN

-- 2:00 pm ET: Attends event with voters, Bloomington, IN

As for the Republicans. . .

JOHN MCCAIN

-- 9:00 am ET: Delivers speech to voters at event, Annapolis, MD

-- 4:45 pm ET: Delivers speech to voters at event, Pensacola, FL

At the White House and Beyond. . .

PRESIDENT BUSH

-- 1:50 am ET: Delivers speech at the National Bank of Savings, Bucharest, Romania

-- 4:55 am ET: Meets with the President of Romania, Neptun, Romania

-- 6:25 am ET: Holds joint media availability with the President of Romania, Neptun, Romania

-- 9:15 am ET: Meets with the NATO Secretary General, Bucharest, Romania

POLITICAL NEWS STORIES ON ABCNEWS.COM

ABC News' Ed O'Keefe Reports: McCain the 'Punk' Goes Back to School LINK

ABC News' Marcus Baram Reports: Daddy Issues, War Lust in Oliver Stone's 'W' LINK

ABC News' Ed O'Keefe Reports: Pelosi: Bush Should Consider Boycott of Olympics' Opening LINK

ABC News' Mark Mooney Reports: Obama-Clinton Fuel Record Primary Turnout, But Will Enthusiasm Last? LINK

ABC News' Anna Schecter Reports: Undoing the Abramoff Effect Continued LINK

ABC News' Jake Tapper Reports: Obama's Oil Slick LINK

ABC News' Russell Goldman Reports: Do Dueling Dems Give McCain an Advantage? LINK

ABC News' Eloise Harper Reports: Hillary Clinton: Rocky's Apprentice LINK

ABC News' Jake Tapper Reports: It's the "Rocky" Road for Hillary Clinton LINK

ABC News' John Berman Reports: If You Miss McCain's Speech --Just Buy the Book LINK

ABC News' Jake Tapper Reports: On Chelsea, Monica, and the Scandal That Dare Not Speak Its Name LINK

ABC News' Eloise Harper Reports: Clinton Strikes a Joke for Fools Day LINK

ABC News' Sunlen Miller Reports: Obama: McCain's Policies a Problem, Not His Biography LINK

ABC News' Z. Byron Wolf Reports: No April Fool's Joke - Senators Seek Bipartisanship to Address Mortgage Crisis LINK

POLITICAL VIDEO ON ABCNEWS.COM

Hillary Pulls April Fools Joke

Clinton fools the press and challenges Obama to a bowl-off for delegates. LINK

McCain's Waiting Game

With Democrats consuming all the political oxygen, what does Sen. McCain do now? LINK

Bill Clinton Heckled Again

The former president is interrupted by rowdy crowd members in Selma, OR. LINK

Clinton Compares Herself to Rocky

Sen. Clinton says like Philly icon Rocky Balboa, she will never quit. LINK

McCain a Teacher's Pet?

Sen. McCain returns to his alma mater to discuss the importance of education. LINK

Bush Vs. Putin

President Bush defies Russia's President Putin and supports Ukraine's NATO bid. LINK

McCain Sets the Record Straight

The presumptive Republican nominee weighs in on Nancy Pelosi's comments. LINK

Nancy Pelosi on Olympics, Election

House Speaker addresses a possible Olympics boycott and the presidential race. LINK

Chelsea: Lewinsky 'None of Your Business'

An N.C. State student re-asks Chelsea Clinton about the Lewinsky affair. LINK