First, the thornier side, is about sex. The viewing public loves sex. So, naturally, the racier the sexualization of television, the more viewers you'll get. Whether in Utah or Los Angeles, people watch complete garbage.
The pro-censorship guysThen, of course, there's a powerful section of the population, maybe waning in power now, that wishes to impose what might be described as a neo-Christian (or neo-Judeo-Christian*) morality on the public. John Lofton is an early example. In the 1980s, he was playing the quintessential American 1980s conservative: angry, dumb, beedy-eyed, wearing large-rimmed glasses, and ready to sink his teeth into anyone who dares to disagree with him (which, to him, is probably tantamount to disagreeing with the Bible). Today, he runs a blog after having left the Republican Party because they're too unbiblical.
It's said neo-Christians ("Christian right") have theological motivations at times, though I somehow doubt theology was ever the overarching motivation. If they resemble an earlier Christian movement, it's the Catholic Church in the Middle Ages—people believed in them, and they believed in Jesus, but not too many people really knew what they were talking about. In the jolly Middle Ages, there wasn't much in the way of enforcement of rules, but there was a lot of talk about rules. Hell was reserved for pretty serious heresy (or Jews). Like the 1970s-1980s, capitalism and borrowing was the new vogue. The bourgeois become popular in government because they were able to manage finances. The church was a big receiver of income (in the climax of the neo-Christian movement, in the early 2000s, there was a lot of talk of federally-financed, likely unconstitutional "faith-based initiatives"). While this was going, the church backed off from its restrictions on usury, as secular governments found themselves needing to borrow to finance wars and later explorations. It was only in the early modern era that religion surged in violence again (maybe that's next in the 21st century?).
In any event, neo-Christians weren't necessarily fundamentalist Christians, and some still aren't. Most are Republicans, but occasionally there's a Democrat (Joseph Lieberman) or Libertarian thrown into the mix. Most subscribe to some form of evangelical, highly eschatological Christianity, but some are Catholics or even Jews (Leiberman again, or Bill Kristol). Heck, some are Mormons—witness the recent idiotic speech by Mitt Romney, who preaches religious toleration to a point.
If anything, neo-Christians may not even agree about very much. They agree that abortion should be banned, they agree that federal power can be used to enforce morality (to varying extents), and they agree that at least parts of the First Amendment really shouldn't have any teeth or no heed should be paid to it at all. In all other ways, they have wide-ranging beliefs, though it often seems otherwise because they're willing to sacrifice almost everything else over their core issues, allowing other interest groups to fill in the vacuum (this is where people like Kristol and other Republican Party sects like big business come in).
The neo-Christian guys first cropped up definitively in the 1970s, though elements of their theology and even influence certainly can be traced back decades, if not centuries. They were around before Roe v. Wade (1973), though Roe certainly boosted them. Pat Robertson had The 700 Club in the 1960s and The Late Great Planet Earth (by ex-riverboat captain Hal Lindsey) was written before Roe (1970). Less polemical, but also at least on the fringes of that movement, was Billy Graham.
By the 1980s, after hot issues like the Vietnam War and Watergate had cooled down, these neo-Christian guys took Washington and the airwaves by storm. They never had full control of the House and Senate until 1994, but they set the legislative tone from 1980 until 1992, and then from 1994 until 2007. They only managed full control of both the Congress and the White House for most of the period between 2001 and 2006. There was a short lull from late 2001 until early 2003 when Vermont Republican Senator Jim Jeffords left the party and handed control of the Senate over to the Democrats (he decided not to seek reelection).
Regardless, from the 1980s on, neo-Christians set the social agenda, and deferred to other sometimes overlapping, sometimes contradictory sections of the Republican Party to set the economic agenda. Their power to persuade was unprecedented because they learned to master the airwaves as a tool for spreading memes. Constant, non-stop repetition of their ideas made their ideas popular, even when those ideas were obviously stupid. Ronald Reagan's moronic economic policies, which we're still paying for in 2007, sounded great: cut taxes, cut spending, cut regulations, get the government out of our lives, spend a lot on the military (I know, but they don't quite contradict). Either way, he really only managed to cut taxes and some regulations. Meanwhile, Ronnie had no problems using the federal government to thrust social policy on people: he presided over raised drinking age to 21. Meanwhile, the neo-Christians managed to poison to the 'L' word and keep the focus of dialog solely on their beliefs until at least 2005, arguably with a break around 1992 when the mess made in the 1980s and early 1990s was really to much.
Keep in mind, however, this movement was a lot more earnest early on than it was by the 1990s, or even in the 2000s when it was partially eclipsed by neoconservatism.
* I'm just going to stick to neo-Christian as the term, because it's short.