WASHINGTON — Maybe Joe Biden had to flip on the question of taxpayer funding for abortion in order to win the Democratic presidential nomination.
All of his rivals supported that funding, and the party has become more and more aggressive on abortion. Where the 1990s Democratic platforms said abortion should be "safe, legal and rare," the 2016 platform dropped that defensive note and included an explicit call to end the longstanding ban on using federal Medicaid funds for elective abortions.
But there will be a cost to Biden's choice.
First, it puts Biden on the unpopular side of the issue. Advocates of taxpayer funding can point to polls saying that most people support abortion — but that's true only when the polls have been worded not to mention taxpayer funding. A 2016 poll that clarified it was asking about Medicaid paying for abortions found that 58 percent of the public opposed it.
Second, it means that the Democratic nominee will find it more difficult to portray Republicans as far right on abortion.
Republican opponents are on the wrong side of public opinion on several questions about the issue. Most people say they would like to see Roe v. Wade survive, for example. If Biden had stuck with his opposition to taxpayer funding and won the nomination, he might have been able to draw a contrast between his own moderation and the Republicans' extremism. But the Democrats have now drawn more attention than ever before to a question where they're the ones who want a big change in abortion policy that most people oppose.
Third, it undermines Biden's chief asset in the primaries: the claim that he's electable. Liberal Democrats may not like Biden's record on crime or Iraq, but his relative moderation is supposed to make him a better bet to win in November 2020. If the left can browbeat him into discarding his moderate stands, though, where's the upside?
Fourth, it also undermines the message that Biden is a steady hand. If a stance he held for decades can be swept aside after a day of criticism from his opponents and interest groups — if he could so badly misunderstand the currents in his party — then does all his vaunted experience really add up to good judgment?
Fifth, the way the flip-flop happened highlights Biden's age. Last month, the former vice president was asked about government funding of abortion at a campaign event and appeared to say that he now favored it. Then the campaign explained that Biden had "misheard" the question and still opposed funding. After intense criticism, Biden then said that he supported funding.
Biden has faced two big challenges in this race. One is ideological: Is he too moderate for today's Democratic Party? The other is personal: Is he too old to be the nominee and the president? The way his campaign has handled the taxpayer-funding question has brought both critiques together.
Biden is surely aware of some of these costs. There's a reason he hesitated to renounce his old stance. He probably decided that the Democratic Party's current level of devotion to abortion rights meant that he had to do it.
NARAL, the abortion-rights group, was triumphant after Biden made his announcement. I'll bet it brought a smile to President Donald Trump's face, too.
Ponnuru is a Bloomberg Opinion columnist and a senior editor at National Review.