The letter was written by Sojourners, which is a Washington, D.C.-based national network of Christians which focuses on social justice issues. The letter can be seen here, in full. The letter is titled "Listen to your Pastors."
IN part, the letter said, "In every one of our congregations we have programs that help those in need with jobs, clothing, food, or counseling.
"Still, we can't meet the crushing needs by ourselves. (Faith-based) nutrition programs only make up 6 percent of total feeding programs in the country while the government makes up 94 percent.
As Christians, we believe the moral measure of the debate is how the most poor and vulnerable people fare. We look at every budget proposal from the bottom up --- how it treats those Jesus called 'the least of these" (Matthew 25:45)."
Matthew 25:45, from the King James Bible: "Then shall he answer them, saying, Verily I say unto you, Inasmuch as ye did it not to one of the least of these, ye did it not to me."
Simplistically said, help the needy, or you're not helping me. The implication is, would you want to ignore the needs of the Son of God?
So why do the right-wingers who claim to be Christians, fight against Universal Health Care? Why does the GOP want to end Social Security, Medicaid, and Medicare? It's because, as was discussed on Norman Goldman recently (Thursday, June 14, in fact, with free podcasts on his site), these are not true Christians. Instead, they are Calvinists. Calvinists, in a nutshell, believe that those who have ills (sickness, lost job, whatever) "have it coming to them." This is an extremely simplistic description, mind you.
Thus, they also do not believe that anyone should receive help. "It's your fault, you deal with it." Ask one of them who Jesus would insure to get a blank stare. Or ask them if Jesus would care about debt when it came to helping the needy (and the answer should be obvious: debt should not be considered, we should help everyone who needs help).
In addition to the letter, Sojourners has a blog post about the issue.