With just under three weeks to go til the Pennsylvania primary, there's a lot of air space to fill. Naturally, the state polls provide plenty of fodder. And, this week, there are a slew of polls to examine.

Over the past two days, four Pennsylvania polls have been released. Rasmussen caused a stir yesterday when it showed Clinton's lead had dropped to five: 47 - 42. Shortly thereafter, SurveyUSA released a poll giving Clinton a 12-point lead: 53 - 41 (down from her expected 19 point margin of victory). This morning, Quinnipiac gave its latest numbers for PA - Clinton was up by 9: 50 - 41. Then, this morning, came Public Policy Polling (PPP) with the first poll showing Obama in the lead, 45 - 43. The PPP lead for Clinton was 26 points a couple weeks ago. The PPP poll has a lot of people scratching their heads.

So what does it mean? Good question. Keep in mind that Pennsylvania is supposed to be Clinton's ultimate firewall state. She's not only supposed to win -- we've all been lead to believe she is going to win BIG -- like 15 - 20 points big. PA has to be a blowout for Clinton.

There are still 20 days til primary day. But, seems like this week, Pennsylvania got a lot more interesting. The big question is whether Clinton can meet the high expectations that her campaign has set.

And, I find it helpful to watch the trendline on Pollster.com: