With just three weeks to go until the Pennsylvania primary on April 22, the contentious Democratic race has the feel of the early voting states again.

Sens. Hillary Clinton and Barack Obama were both in eastern Pennsylvania courting voters yesterday. Clinton was beginning a three-day tour of the Keystone State as Obama went into the fourth day of a six-day tour.

He stopped in Lancaster and Reading, while she spoke in Harrisburg and here in suburban Philadelphia. Likening herself to a political Rocky, Clinton said she had absolutely no intention of conceding the Democratic race.

Both campaigns are bringing out the big guns to boost their chances. Clinton enjoys support from Philadelphia’s Mayor, Michael Nutter, and Gov. Ed Rendell. Obama recently picked up the endorsement of popular U.S. Sen. Bob Casey.

Meanwhile, Barack’s wife, Michelle Obama, will be campaigning in Pittsburgh on Wednesday with Teresa Heinz Kerry, a local icon and the wife of Mass. Sen. John Kerry, the 2004 Democratic nominee and a prominent Obama supporter.

Both campaigns hit Republican Sen. John McCain hard on the economy.

Talking at the Capitol Diner with a pre-selected group of Harrisburg-area voters, Clinton discussed health care, the high cost of college, energy prices and other budget issues hitting Pennsylvania - and all middle-class America.

“The best I could determine, [John McCain's economic] plan would be to not have a plan,” she said to much laughter at the diner. “If he got the 3 a.m. call on the economy, he would just let the phone ring and ring and ring.”

In Lancaster, Obama also critiqued the Republican nominee-to-be, saying his campaign was effectively a plan to launch a third Bush term. This included, in a familiar theme, an indictment of McCain’s Iraq war policy as well.

You can only put so much stock in one poll, but a Rasmussen Reports survey conducted yesterday shows Clinton’s lead in the state may be shrinking.

The latest Rasmussen poll in Pennsylvania shows Clinton leading Obama by just five percent, 47-42. That five-point edge is down from a 10 percent a week ago, and much more than that in surveys conducted by other agencies.

To close the gap, the Obama camp has combined campaigning door-to-door with a media blitz - he’s outspend Clinton 2-to-1 in the state.

If Barack Obama is somehow able to upset Hillary Clinton in the Keystone State, it would effectively end the race for the Democratic nomination.

Clinton remains ahead, however, and every Pennsylvania primary analysis seems to favor her. We’ll see if this poll is just an aberration or part of a trend.

A Clinton victory, which is by all accounts expected, would put North Carolina and Indiana (May 6) in the spotlight as she clings to her slim chances.