Though Americans as a whole have kept a fairly steady view on abortion over the past decade, there have nevertheless been sizable shifts in public opinion within specific geographic regions during that time, according to a Pew Research survey released Monday.

The result has been an increasingly polarized America when it comes to abortion, a fact that helps explain the sudden push for (and subsequent backlash against) new anti-abortion measures nationwide.

Fifty-four percent of respondents in Pew's poll said abortion should be legal in all or most cases, versus 40 percent who said it should mostly or always be illegal. However, there was a vast gulf between the most liberal and most conservative states on the issue. While three-fourths of New Englanders in the survey supported abortion in most or all cases, just 40 percent of "South Central" dwellers — a cluster of eight states that includes Texas, Alabama, and Mississippi — said the same.

That gap is growing, too, as support for abortion has eroded in Midwestern and Southern states over the past ten years.

In the mid-90s, a majority of respondents in every geographic region said abortion should be legal in all or most cases. On the low end, fifty-two percent of people in South Central states said they supported abortion most of the time, while at the high end, 70 percent of New Englanders supported abortion most of the time. That made for an 18-point gap between the most and least accepting regions.

Since then, the split has nearly doubled to 35 points.

The shift helps elucidate why abortion has suddenly emerged as a driving issue in Republican-led statehouses in many areas of the country.

State legislatures have passed a wave of restrictive abortion measures this year — 43 in the first six months of 2013 alone. Most prominently, Texas used a special legislative session to circumvent a filibuster and pass a bill that will ban abortions beyond 20 weeks into pregnancies and impose new restrictions on the state's abortion providers.

Though those efforts have prompted a vocal outcry at the national level, they're actually fairly representative of public opinion at the state level. In states that ban abortions at 22 weeks or earlier, including Texas, 49 percent of respondents said they opposed all or most abortions, versus 44 percent who said the opposite.

While national Democrats could turn the War on Women into a winning political argument in 2014 and beyond, they're unlikely to successfully replicate that formula at the local level in conservative states. That's why Wendy Davis, despite her epic filibuster, has virtually no chance of becoming Texas' next governor.