He probably will test that power - and the theory, which he rejects, that economic anxieties have marginalized those issues - by seeking the Republicans' 2012 presidential nomination.
Santorum had one of the Senate's most conservative voting records and was floor manager of the most important legislation of the 1990s: the 1996 welfare reform, which Clinton vetoed twice before signing. In 2000, Santorum won a second term with 52 percent of the votes, and he was elected third-ranking Republican leader in the Senate. In 2006, a miserable year for Republicans, he lost 59 to 41 percent.
How can he, having lost his last election, run for president? Isn't he a spent political force? Well, was Richard Nixon defunct after losing the California gubernatorial race in 1962?
Santorum has made nine trips to New Hampshire, where he has hired a chairman of his state political action committee and a state director, and is returning soon. He has been that many times to two other early delegate-selection states, Iowa and South Carolina, and has other trips to those states scheduled.
Seven reasons why he has not committed to running are his children, ranging in ages from 19 to 2. The Santorums take parenting very seriously: All but their youngest child have been partially home-schooled. The youngest, Bella, is severely disabled with Trisomy 18, a condition caused by a chromosomal defect that prevents more than 90 percent of its victims from reaching their first birthdays.
About his presidential run, he says, "My wife is sane, therefore she doesn't want me to do this." But both she and he are passionately right-to-life and dedicated to trying to reform today's abortion culture, which is increasingly comfortable with treating inconvenient lives, including those like Bella's, as disposable.
Santorum appears four to six times a week on the Fox News and Fox Business channels, which are watched - particularly the former - by much of the Republican nominating electorate. And for three hours every Friday he hosts William Bennett's nationally syndicated radio program, which also has a mostly conservative audience.
Santorum does not ignore economic issues, but as a relentless ethicist, he recasts those as moral issues: "What is European socialism but modern-day monarchy that 'takes care' of the people?" He is, of course, correct that America's debt crisis is, at bottom, symptomatic of a failure of self-control, a fundamental moral failing.
The first event of the nominating process, Iowa's Republican caucuses, are, Santorum says, a bifurcated event. One part concerns born-again and evangelical Christians, who are 60 percent of caucus participants. The other part involves everyone else. This is why Mike Huckabee won Iowa in 2008 and why in 1988 Pat Robertson finished a strong second to Bob Dole and ahead of George H.W. Bush.
Three people who might have competed, or still might compete, with Santorum for voters intense about social issues include Indiana Rep. Mike Pence, who has decided against running. And Huckabee, who is doing well as a Fox News contributor. And Sarah Palin, another Fox luminary, would have the most to lose financially from running. Santorum thinks "the left is trying to goad her into it," hoping she would be weak among the independent voters who decide most elections.
Tim Pawlenty, former governor of Minnesota, a state contiguous with Iowa, is running hard and has published a book with a strong religious theme, but Santorum doubts that Pawlenty has the passion requisite for connecting with "values voters." That is a Santorum theory.
Here is another: If unemployment is still above 9 percent in 2012, almost any Republican can win, and if there is a convincing recovery the party had better nominate someone who can energize its base.
That is only a theory, but this is a fact: Social conservatives are much of that base, are feeling neglected and are looking for someone like Santorum.