By Pamela Gentry, Senior Political Producer 

Posted March 28, 2008  - The stress level in the Clinton campaign became more evident this week as they struggled to get pledged delegates to switch, super delegates to back the New York senator and finagle a way for do-overs in Michigan and Florida.

The week didn’t end much better than it started; today Pennsylvania Sen. Bob Casey endorsed Illinois Sen. Barack Obama.  This endorsement looks like another push back from a super delegate sending a coded message to Sen. Hillary Clinton (D-N.Y.) that Obama should be the nominee.   

This endorsement is the second high profile introduction for Obama on the trail in what should be considered “Clinton territory.”  On Thursday, New York Mayor Michael Bloomberg introduced Obama before he delivered his speech on the economy in the Big Apple. Bloomberg hasn’t endorsed any candidate, but his appearance with Obama has generated  a variety of speculation.

Casey will join Obama on a six-day bus tour throughout the state in hopes of boosting his appeal to Pennsylvania voters.   Clinton has been favored in the state and leading in polls there, so the Obama camp has decided to increase their visibility and reorganize the team on the ground.  

They announced they’ve replaced Pennsylvania campaign manager Jim DeMay with Paul Tewes, for a more aggressive strategy in the state.  Tewes is credited with Obama’s impressive win in the Iowa caucuses.

The Clinton camp was delivered another harsh blow from polls showing the controversies over the comment by the Rev. Jeremiah Wright haven’t been a big negative for the first term Illinois senator.     

The survey by Pew Research Center found while both Democratic candidates were favored for commander and chief over Republican John McCain (R-Ariz.), Obama garnered 49 percent of Democrats surveyed to Clinton 39 percent.  (The margin of error 5.5 percent)

But negatives have been mounting towards the New York senator according to a survey released Thursday by NBC and The Wall Street Journal.  The poll found Obama with a positive personal rating of 49 percent, down 3 percent from two weeks ago, and Clinton with a 37 percent positive personal rating, “Her lowest rating in the poll since 2001,” according to the paper.

But Clinton supporters are flexing their muscles too.  Earlier this week a letter signed by 21 donors to the Democratic Congressional Campaign Committee  (DCCC) was sent to House Speaker Nancy Pelosi warning her to back down on her direction for super delegates.  Pelosi had suggested it would be dangerous for super delegates to override the pledge delegates in the party.
The letter stops short of delivering a direct threat, but says, “We have been strong supporters of the DCCC. We therefore urge you to clarify your position on super-delegates and reflect in your comments a more open view to the optional independent actions of each of the delegates at the National Convention in August.”

Clinton’ communication director Phil Singer told reporters the campaign was given a “heads up” about the letter but they didn’t contribute to its content.

If the Dems keep at it like this, President Jimmy Carter may be called in to monitor the convention.