
(CNN) -- Pennsylvania Rep. Joe Sestak has informed supporters he plans to challenge Sen. Arlen Specter in the Democratic primary, a spokesman for the congressman tells CNN.
Jonathon Dworkin, Sestak's communications director, confirmed the authenticity of a handwritten letter from Sestak - first posted on the Web site Talking Points Memo - to a supporter in which the congressman states, "I intend to run for the U.S. Senate."
Dworkin also confirms quotes from Sestak's sister to TPM stating, "He intends to get in the race,..."In the not too distant future, he will sit down with his wife and daughter to make the final decision."
Sestak’s decision to challenge Specter, who recently switched his party affiliation from Republican to Democrat, puts the congressman at odds with Democratic congressional leaders and President Obama. The president and the congressional leaders have endorsed Specter for re-election in 2010.
Sestak will appear on CNN's The Situation Room to discuss the race at 6:45 p.m. EST.
Text of the letter:
"I am writing you as especially dear supporters to let you know I intend to run for the U.S. Senate...my candidacy's credibility will have much to do with my fundraising success by the 30 June FEC filing deadline at the end of this quarter. Would you help me bring the change for the future we Pennsylvanians need[?]"


Go for it Joe! Spector is out for himself and not for the democrats!
Too bad Arlen.....lets get some new blood in the race on both sides vs. a 79 year old professional political hack
Outstanding!
I have NEVER even remotely considered making a campaign contribution to a Democrat – but I am tempted to in tis case!!
Great. Challenge for the right to Fire Specter. I applaud Sestak's decision to challenge him. Specter is a good centrist but the move to the other party just to keep his job irks me to no end, and cheapens his principles as well as the seat in the senate he keeps....
I am glad to see another Dem in the race in PA. Almost immediately after he switched parties Specter admitted that he will not support party decisions. This is reason enough for a true Dem to have the seat. I wish I were a PA resident to vote for Sestak. We do not need another Liberman who votes to suit his own interests. We will need a united front on many occasions in the future to keep the republican negativity at bay.
Fantastic.I wonder how Specter will convince the Dems of PA that he really hold their values and aspirations after a lifetime on the other side of the fence working against them. If Specter really wanted to see what it was like on the other side he should have just gone and visited Larry Craig instead.
Go Joe
good
Sestak can beat the Republican who is hiding in the Democratic party. Why take a fake Democrat when you can get a real one??
He needs some folks to challenge him – he's not a real Democrat.
People in hell have better chance of getting ice water.........
Good. I hope Specter gets what he deserves. Leaving the Republicans was totally gutless and self serving. The only thing Specter is concerned about is himself and winning an election. He showed zero loyalty to the Republican party. In a time win this country needs people who will stand up for what is right, he simply stood up for what was best for Arlen. I hope the good people of Pennsylvania recognize that Specter doesn't give one hoot about them. Seems to me all he really cares about is his own career and reelection.
He is an excellent person and a fantastic politician. I was blessed to have worked for him on the 2006 Election Trail where he defeated incumbent Curt Weldon. He is an American Hero and will serve the people of Pennsylvania beautifully.
Good, I'm glad someone is running against him. Sen. Spector is a disgrace to our country. He doesn't care about the country and its future. He switched parties so he wouldn't lose. Not someone I would want in the Senate
Good for Rep. Sestak!!! I'm tired of these political people telling us who we should get for our next Senator. anyone at this point would be better than our current senator.
Sestak, would be the better candidate. Alan Specter is a plant. He can't be trusted when a critical moment comes. Specter will vote with the GOP when it gets controversial. That is all he has left. Don't trust anyone that trades sides.
Specter is a no good backstabber.......he's nothing now having lost all of his seniority and is solely at the beck and call of the Democrats....
The people of Pennsylvania know now that he can't be trusted and is just another Judas in the weeds....you'll beat him easily as no one wants a slimy backstabber....
I'm in Virginia, but YES, I will help you defeat Specter!!
He's probably just as shady as Specter and maybe as shady as Obama.
This will be interesting to watch. Specter's support is pretty thin, but he is very well known and can probably raise a lot of money for the run. Sestak, on the other hand, is an unknown outside of his area, which means he'll have to spend a ton just to get noticed...
I'm not sure what the polling says right now, but I personally would rather vote for a "real" Democrat; someone who has had the guts to stand up for those beliefs his entire career than I would vote for Specter, who, let's face it, just wants to get elected again.
And I don't think I'm alone...
Take a rest Joe! Help your party and wait it out. Give Specter another 6-year term to help getting Health Care in place. His senority and experience is useful. Then liklly he will retire and you can be there for many years after that. Don't be too anxious or too quick to try the Senate seat hat on now. If you lose this race, it may be a very long time before your time comes up again. People do remeber and it maybe now what you want them to remeber that you tried to oust Arlen.
Good. I hope Specter loses. I don't even care whether he is beaten by a Pub or a Dem. You can't rust a turncoat.
Isn't the point of democracy that we choose our own representatives, not have them chosen for us.
Go Joe Sestak!
I heard Sestak speak and no doubt he's a thoughtful person. He has served this country with honor and I will support his candidacy and contribute what I can go Sestak
Way to go, Sestak! Tell Obama to keep his nose out of your business! And where do I send you $500?
I live in North Carolina, and I will send Sestak money – as much as I can afford. We need a REAL democrat in that seat, not a faux democrat like Specter.