Marriage plays a key role in strengthening civil society and reducing poverty. Families of married couples, for example, are approximately six times less likely to be poor than single-parent families. That suggests marriage is one way to reduce the growing dependence on government welfare programs.

It also turns out that married couples think about the world quite differently from their single counterparts. When it comes to their political preferences, married couples tend to back Republicans while single men and women support Democrats. That was the case in 2008 and it’s once again shaping up to be a dividing line in 2012.

Pollster John Zogby noted the distinction in a recent piece on the “marriage gap,” which he called more dramatic than the gender gap. Zogby runs through the numbers:

In an analysis provide by my colleagues at Gallup after the 2008 election, all married voters supported Senator John McCain over his Senate counterpart Barack Obama by a 12 point margin – 56% to 44%. Single voters favored Obama overwhelmingly by 30 points – 65% to 35%. But the gender characteristics of voter patterns were nearly canceled out by the marriage gap. In 2008, married men gave McCain a 16 point advantage over Obama – 58% to 42% — while single men pounded the Arizona Senator by 26 points – 63% to 37%. Married women supported McCain by 6 points, 53% to 47%, but it was Obama’s 32 point margin among single women – 66% to 34% — that provided him with a comfortable margin of victory.

We see every indication thus far that married voters will turn out and we see pretty much the same patterns as in 2008 in our 2012 polling. Thus, Romney leads Obama among married voters by 13 points – 50% to 37% — which is about the same as McCain’s margin in 2008. But Obama’s 18 point lead among all single voters – 52% to 34%– is far short of his performance four years ago. Again the Republican leads among married men by 18 points – 51% to 33% — even better than McCain’s margin. Obama’s margin in our poll of 27 points (56% to 29%) among single men is also on the mark with 2008. Romney leads among married women this time by 10 points (50% to 40%), better than McCain’s 6 point margin. But, while Obama leads among single women by 21 points – 50% to 29% — this does not match his 32 point margin in 2008. Even worse for Obama, at this point in time, is that 21% of single women are undecided. This is a strong suggestion that they may not even vote.

These numbers paint a sharp contrast between married and single voters. And while married couples don’t think monolithically about policy issues, there’s clearly something that draws more of them to conservative ideas. Even more striking, however, is the larger number of single men and women who come down on the other side.

With marriage on the decline among the poor and middle class, this should be a wake-up call for conservatives. Leaving politics aside, the benefits of marriage are so significant — for personal success and educational attainment — that it’s worth focusing on ways to strengthen and promote marriage.