The U.S. political discourse on abortion seems unable to shake the hopelessly simplistic binary between life and choice of the 1970s and 80s. The “you’re either for it or against it” approach is problematic in American politics more generally, but it does particular violence to the views of most Americans about abortion. A majority of Americans claim the term “pro-choice” describes them somewhat or very well while simultaneously claiming that the term “pro-life” describes them somewhat or very well. Given this complexity, perhaps it is not surprising to find that 61 percent of Americans believe that abortion should be broadly legal during the first trimester—while only 27 percent support the choice during the second.

As if the lazy binary isn’t bad enough, the political maneuvering of the major parties around the abortion debate has been nothing short of bizarre. It has led Democrats and Republicans to take positions on abortion in line with something that I call the “Costanza Strategy.” Fans of Seinfeld will remember the hilarious episode where George “does the opposite” of every instinct he’s ever had and it turns out great for him. On abortion, the two parties also seem to exhibit the opposite of their usual political instincts. Republicans claim to be skeptical of big government and push for the autonomy and freedom of individuals to make private decisions. Except when it comes to abortion. Democrats want government’s protection for the voiceless and marginalized over and against the autonomy and freedom of those who have power over the vulnerable. Except when it comes to abortion.

Unsurprisingly, the Costanza strategy is a relatively new approach for the parties, which until recently exhibited a much broader array of views on the subject of abortion. When he was governor of California, Ronald Reagan signed the law permitting abortion in that state. As a national Republican candidate though, he somehow became a hero of the pro-life movement. He also appointed George H.W. Bush as his running mate, another Republican with a pro-choice record. When the elder Bush ran for president, he too switched to become pro-life. The former pro-choice governor of Massachusetts, Mitt Romney, also shifted away from his pro-choice position for his own run at national politics. Similar shifts took place with Democrats: Party leaders such as Ted Kennedy, Jimmy Carter, Al Gore, Joe Biden, Jesse Jackson and Bill Clinton all expressed views that were strongly skeptical of abortion—until the Costanza strategy kicked in. Then, like their Republican counterparts, they were forced to get in line with the new abortion orthodoxy.

And, to this point at least, the parties have been given no incentive to do anything differently. Quite the contrary, in fact: The parties have a strong interest in the status quo. Consider Juan Williams’ argument that both Republicans and Democrats benefit from keeping the abortion conversation locked in failure. It is one of the best wedge issues for producing money and for motivating their electoral bases. This is why the same fixed pattern of debate with the same prescribed divisions recurs over and over again, election-cycle after election-cycle. The Costanza strategy works, despite its incoherence, because it keeps the current arrangements of political power safe for those who benefit from them.