Three new polls out Wednesday show how close the Democratic Senate primary in Pennsylvania has become.

One poll has incumbent Sen. Arlen Specter (D-Pa.) in the lead, one poll has challenger Rep. Joe Sestak (D-Pa.) in the lead and the other has the race tied.

Specter leads 44 percent to 42 percent in a Quinnipiac poll; Sestak leads 38-36 in a Franklin and Marshall poll, and a Muhlenberg survey has the two men tied at 45 percent.

The primary is May 18th.

It's a big fall for Specter. Polls at the end of March had him leading Sestak by 20 points. Sestak, however, had no where to go but up, particularly as he built his name recognition around the state, but the recent primary defeats of incumbents Sen. Robert Bennett (R-Utah) and Rep. Alan Mollohan (D-W.V.) has to have Specter worried. 

"Sen. Arlen Specter has a history of winning close elections and he'll need that to continue because his once commanding lead is gone. His margin over Sestak is too close to call," wrote Peter Brown, assistant director of the Quinnipiac University Polling Institute, in his analysis of the race.

There may still be voters to win over. The Franklin and Marshall poll show that 15 percent remain undecided.