It is clear to even the most distant observer that family values are a big issue in United States politics. Among the Republicans vying for selection as presidential candidate so far two have been touched by sexual scandal: Herman Cain is out of the field but Newt Gingrich may survive.

There’s another interesting angle to the other remaining contenders, however, and that’s their large(ish) families. This was noted by New York Times columnist Mark Oppenheimer:

The Republican presidential field has produced a lot of babies. There is Mitt Romney, father of five sons. Ron Paul, an obstetrician by training, is also a father of five, and his campaign Web site credits him with bringing 4,000 babies into the world. Newt Gingrich and the recent dropout Rick Perry have only two children each, but Rick Santorum [pictured], who has said contraception is “not O.K.,” has seven children, and so does another former candidate, Jon M. Huntsman Jr.

This seems to be partly explained by religion -- Mormonism for Mitt Romney and Catholicism for Rick Santorum, for example. Does this make them more -- or less -- attractive to Republicans of other religious denominations?

Oppenheimer suggests that 50 years ago “a Santorum-size family would have been seen as a marker of exotic, sinister religiosity” by evangelical Protestants. Big families “were for immigrants and Catholics, or for the rural poor.” Since then, however, there’s been a big shift in evangelical thinking about contraception and big families -- witness the famous Duggar family (“19 kids & Counting”) and the Quiverfull movement.

Family scholar Allan Carlson (a Lutheran) has just published a book called Godly Seed: American Evangelicals Confront Birth Control, 1873-1973. He told the Times that as recently as 10 or 20 years ago Mr Santorum’s rejection of birth control “would have been an immediate no” for nearly all Protestants.

Today, even evangelicals who use contraception have a much better understanding of the moral and social objections to it. Jenell Paris, who teaches at Messiah College in Pennsylvania, is quoted by the Times:

“Our understanding of hormonal birth control methods — the pill, the patch, the ring — have changed,” said Dr. Paris, alluding to those who believe, on scant evidence, that these methods of birth control can contribute to long-term infertility. “Abortion politics have changed. Views of women in the workplace have changed. Feminism has changed. All that has contributed to a number of evangelicals embracing a no-birth-control policy, or at least making it comprehensible.”

Almost 40 years after Roe v Wade (anniversary yesterday) and the termination of nearly 60 million lives in the USA alone, the routineness of abortion in a contraceptive culture must surely be the major contributor to this change of mind.