This comparison comes from the Guttmacher Institute, which finds that states passed 205 abortion restrictions between 2011 and 2013, more than the 189 laws passed between 2001 and 2010. Nearly half of the laws - 45 percent - fell into three categories: targeted regulations of abortion providers, bans on abortions after 20 weeks and restrictions on medical abortions. "States enacted 93 measures in these four categories from 2011 through 2013, compared with 22 during the previous decade," the Guttmacher analysis finds.

What made 2010 such a boom year for abortion restrictions? It's hard to pinpoint a particular reason, but a few factors do stand out. First, Republicans took control of lots of state legislatures in the 2010 midterm elections, allowing them to pass more restrictions than was politically feasible in the past. The Affordable Care Act also ignited a fight over abortion policy, particularly whether federal funds would help pay for abortions (when Americans used their tax subsidies to purchase health insurance coverage). That fight spilled over to state legislatures - the ones that Republicans had recently come to control - and many passed laws restricting insurance coverage of abortion.

Lastly, the focus on late-term abortion, with the 20-week abortion bans, likely played a role, too. As the Guttmacher Institute reports, those bans proliferated quickly, after Nebraska passed the first such law back in 2010. While the majority of Americans do support legal abortions in the first trimester of pregnancy, support for abortion rights falls significantly when you get into second and third trimester terminations. That drop-off in public support could have laid the groundwork for the success of the late-term restrictions.