Good question. I've noticed that a lot of these same Christians who are so offended by vulgar words have absolutely no problem wedding God to their particular political party or viewpoint on economic or social issues, especially denying healthcare to the poor, ending Social Security and Medicare, an enhanced Manifest Destiny, continuous war of one sort or another against "heathen" (Muslims, atheists, Democrats, liberals, socialists, Central Americans, gays and lesbians).
Martin Luther, in his Large Catechism, notes that "using God's name in vain" includes making false oaths in God's name in business matters and matters concerning money, possessions and honor, whether publicly in court, in the market or wherever people make false oaths in God's name. Luther also notes that God's name is used in vain when people pledge their fidelity to one another in the name of God, and in the presence of their family and friends, and then are unfaithful.
Luther states that "the greatest abuse occurs in spiritual matters, which pertain to the conscience, when false preachers rise up and offer their lying vanities as God’s Word. Behold, all this is decking one’s self out with God’s name, or making a pretty show, or claiming to be right, whether it occur in gross, worldly business or in sublime, subtle matters of faith and doctrine. And among liars belong also blasphemers, not alone the very gross, well known to every one, who disgrace God’s name without fear (these are not for us, but for the hangman to discipline); but also those who publicly traduce the truth and God’s Word and consign it to the devil." Luther is referring to ministers and politicians who use God's name in an attempt to justify a particular political or social cause, as is practiced in America by certain political, social and economic movements who claim their particular opinion is "the correct viewpoint" because it is what "God's believes." For Luther, this represents the absolute *zenith* of blasphemy.
Luther further states that God has added a solemn threat to this commandment, to wit: "For the Lord will not hold guiltless those who take God's name in vain" and further notes that using God's name as a pretext to justify a particular social, economic or political position will not be condoned nor pass unpunished.