I posted a brief comment about Psalm 127 on SusanG's diary about Jenny Sanford's public statement, but I felt it deserved further attention. Psalm 127 is a prime example of a dog-whistle - a coded message only immediately recognizable to its target audience, much like an HRC sticker is for gays or Bush's mention of the Dredd Scott case was to abortion activists.
The intended target of this dog-whistle? The Quiverfull movement, a particularly creepy subset of conservative evangelical Christians that interprets Psalm 127 to indicate that a good christian should have as many children as is physically possible.
Quiverfull authors such as Pride, Provan, and Hess extend this idea to mean that if one child is a blessing, then each additional child is likewise a blessing and not something to be viewed as economically burdensome or unaffordable. When a couple seeks to control family size via birth control they are thus "rejecting God's blessings" he might otherwise give, and possibly breaking his commandment to "be fruitful and multiply".
Charles D. Provan's 1989 The Bible and Birth Control is credited as strengthening the theological justification for the Quiverfull movement.
Accordingly, Quiverfull theology opposes the general acceptance among Protestant Christians of deliberately limiting family size or spacing children through birth control. For example, Mary Pride argued, "God commanded that sex be at least potentially fruitful (that is, not deliberately unfruitful).... All forms of sex that shy away from maritial fruitfulness are perverted." Adherents believe that God himself controls via Providence how many and how often children are conceived and born, pointing to Bible verses that describe God acting to "open and close the womb" (see Genesis 20:18, 29:31, 30:22; 1 Samuel 1:5-6; Isaiah 66:9). Hess and Hess state that couples "just need to trust God to provide them with the perfect number of children for their situation."
The Quiverfull movement also offers free sterilization reversal procedures for converts, and advocate a complete rejection of birth control, sex education, abortion, and even abstinence within marriage. Many of the largest families in America, including the Duggar family (18 children) are the products of Quiverfull believers.
According to NPR, the average family at the Quiverfull church they visited had 8.5 children. Lou Dobbs rants constantly about his nightmares of Hispanics out-breeding Caucasians. That doesn't scare me. That doesn't even give me the faintest twinge of concern (why would it?). What keeps me up at night is the thought of a group of religious nuts pumping out successors at a rate of one ever 9.5 months.
And they just got a shout-out from the wife of an (ex-)candidate for president.
EDIT (9:52 PM EST): I just realized I forgot to quote Psalm 127, from which the Quiverfulls draw their name and inspiration:
3 Sons are a heritage from the LORD,
children a reward from him.
4 Like arrows in the hands of a warrior
are sons born in one's youth.
5 Blessed is the man
whose quiver is full of them.
They will not be put to shame
when they contend with their enemies in the gate.