I have never felt entirely comfortable with the phrase "God of surprises," a slogan that began as the title of a memoir by a heretical Scottish priest. Still, it's hard to argue that the Author of History is humorless. Who, for example, would have guessed that the 2020 election might end up being fought not primarily on trade or immigration or the economy but on social issues such as abortion?

No one who watched Trump's rise in 2016 could have mistaken him for a Rick Santorum clone. His genius was for kulturkampf of a very different sort — anti-immigrant fear-mongering, mawkish sentimentality about "the troops," "the flag," harder hits in football, 1950s clichés about relations between the sexes. This was brilliant not least because for good or ill most of these things matter a great deal not only to most traditional social conservatives but to millions of Americans who have no strong feelings about abortion and other conservative causes. Now Democrats are helping Trump expand the range of anti-abortion voters — arguably his single most reliable constituency — from religious conservatives to Americans in the broad muddled middle of the most important political debate in this country's history.

Late on Monday afternoon, the Born-Alive Abortion Survivors Protection Act was defeated in the Senate. This legislation would have required doctors to give medical treatment to infants who survive abortion. One Republican, Lisa Murkowski of Alaska, abstained; two others, Tim Scott of South Carolina and Kevin Kramer of North Dakota, were missing in action. Only three Democrats — Alabama's Doug Jones, Pennsylvania's Bob Casey, and West Virginia's Joe Manchin, broke with their party's leadership to support the bill. Among the 44 others who voted against it were all six Democratic senators who have declared for the 2020 Democratic presidential nomination so far. Many of them argued that the 2002 Born-Alive Infants Protection Act already guarantees the rights of abortion survivors, something that is true only in the broadest theoretical sense. The 2002 legislation neither specifies what treatment — immediate care, transportation to a hospital — infants should receive nor imposes penalties upon doctors who refuse to comply.

These senators will be owning up to this vote next year. This issue is not going away. Gov. Ralph Northam of Virginia may have survived his racist folk art scandal, but his attempt to defend a bill that would have made abortion legal up to the moment of birth and, in his telling, even afterwards made an unmistakable impression on the American people. In the space of only a month, the percentage of Americans who identified themselves as "pro-choice" dropped by nearly 10. Some 47 percent of Americans call themselves pro-choice; the same percentage say they are pro-life. This has not been the case in a decade. This sudden and radical shift is unprecedented in the history of the Marist poll, which has asked the same question using the same language for many years.

Americans, like most people, are not especially good at logic. But they have got a conscience. How someone could believe that it is licit to take the life of a human being in utero but murder to deny medical care to the same infant the minute it is no longer in his or her mother's womb is, well, beyond me. To their dubious credit Democrats who support the former and the latter alike are simply being consistent.

This consistency will be their doom. The same Americans who are lukewarm about abortion because it does not seem to affect their own lives, who would rather not discuss the issue, who care more about their tax bill or their dogs, or what Colin Kaepernick is doing before football games, will not countenance undisguised infanticide.

It was their recognition of this complacency grounded in sloppy logic that led the Democratic Party to its previous position of "safe, rare, and legal." It is the same wooly thinking that makes it possible for some moderate Republicans to argue that murdering an unborn baby should be illegal unless the circumstances under which he or she was conceived were sufficiently bad. It makes no sense. It is also genuinely how people feel.

Trump will exploit this, as he is sure to do with the recent judicial decision in favor of including women in a future military draft and the debates about transwomen participating in female athletic competitions. The president does not need to pretend that he has lived a life of chastity and charity in humble service to God. All he has to do is say that letting a baby die on a table is wrong.