The Boston Globe reported

"In remarks to about 50 members of the group Catholic Citizenship -- which encourages parishioners to speak out on issues of public policy -- Santorum decried what he called the growing secularization of American public life.

He traced the problem to Kennedy's 1960 speech to the Greater Houston Ministerial Association, in which Kennedy - then a candidate for president - sought to allay concerns about his Catholicism by declaring, "I believe in an America where the separation of church and state is absolute."

Santorum, who is Catholic, said he was "frankly appalled" by Kennedy's remark.

"That was a radical statement," Santorum said, and it did "great damage."

Unsurprisingly, Santorum has been a hero to the Catholic Right. According to a 2005 profile in National Catholic Reporter:  

"To us, he's the preeminent Catholic politician in America," says Austin Ruse, president of the Culture of Life Foundation, a Washington-based pro-life group. The "us" Ruse refers to are conservative Catholics, loyal to the magisterium, to this pope and his predecessor. "He's a living, breathing, daily communicant who's in the Senate leadership so all of us know that the things that we care about are discussed at the highest levels of the U.S. government," says Ruse.

If Santorum's Massachusetts appearance is any indication, he is positioning himself as the anti-Kennedy and the epitome of the new Catholic pol.  To better appreciate how this is so, note that his remarks are rooted in a little-noticed address he gave last fall in Houston (the text of which is featured on the web site of the neo-conservative Ethics and Public Policy Center.)  The event was evidently positioned as an answer John F. Kennedy's historic speech to the Greater Houston Ministerial Association in which he declared that as president he would not take orders from the Pope and that he respected the doctrine of separation.

Santorum is deeply steeped in revisionist history. But let's focus on just one of his claims.  

The phrase "wall of separation"... comes from a letter written by a founder who didn't even attend the constitutional convention, Thomas Jefferson.

Jefferson's famous phrase has long stood in the way of the ambitions of the theocratically inclined because the Supreme Court has found it to be useful in explaining the meaning of the religion clauses of the First Amendment.  That's why the Religious Right expends so much energy attempting to invalidate it.  

Part of Santorum's line of attack is to undermine the significance of the phrase by highlighting the fact that Jefferson was not present when the First Amendment was written.  While it is true that Jefferson was not around when the First Amendment was written, it is also true that his role as a key architect of our Constitutional approach to the relationship between religion and government is very well-supported by history.  Because this is so, facts are being selectively distorted in order to sustain a counter narrative of American history favorable to key elements of the Religious Right.  Here is how I addressed the 'Jefferson wasn't there' meme in my 1997 book Eternal Hostility:  The Struggle Between Theocracy and Democracy:

One Christian Right leader, John Whitehead of the Rutherford Institute, wrote an influential book, The Separation Illusion, [1977] in which he attack's Thomas Jefferson's notion of the separation of church and state as the key phrase grounding the Supreme Court's understanding of the religion clauses of the First Amendment. Whitehead claims that Jefferson's views are irrelevant because Jefferson was not present when the First Amendment was written.  Christian Right activist David Barton makes the same point in his book The Myth of Separation: What is the Correct Relationship Between Church and State? [1992]

While it is true that Jefferson was, at the time, President Washington's Ambassador to France and was not personally present for the drafting of the Constitution and the First Amendment, his influence is generally acknowledged by historians. In fact, the preponderance of evidence demonstrates the centrality of Jefferson's views in shaping the framer's views of the proper relations between religion and government. In 1777, Jefferson drafted the Virginia Statute for Religious Freedom which was ultimately pushed through the Virginia legislature by his close colleague, then-Governor James Madison, in 1786.  This law provided the theoretical basis for the First Amendment.  Jefferson believed that it was, along with the authoring of the Declaration of Independence and founding the University of Virginia, one of his most important accomplishments. Madison, in turn, is generally credited with being the principal author of both the Constitution and the First Amendment.

Historical distortions are a key ingredient in the success of the Christian Right to date.  This effort to somehow discredit the historical relevance of Jefferson is part of a larger effort to revise American history to suit their contemporary religious and political objectives ....

There are many deceptive propaganda ploys such as Whitehead's to fire up the prospective constituencies of the Christian Right. They are often difficult to address, not only because they can be such a tangle of lies and distortions, but because few outside of their primary intended audience pay much attention.  The effect of all this is the systematic alienation of conservative Christians from mainstream society and the creation of a counterculture which believes that somehow "the truth" has been kept from them through various conspiracies.

If we follow Santorum's logic, John F. Kennedy's views on separation are invalid because Jefferson's views are invalid because Jefferson was not personally present when Madison authored the Constitution and Congress passed the First Amendment.

Whatever else we hear on such things from Santorum, we can reasonably expect to hear many more such things in the not to distant future from Religious Rightists and the pols who pander to them. (John McCain did it last time.)