On Monday, Joe Biden finally broke his monthslong silence on court packing. Previously, he refused to take a stand -- "whatever position I take in that, that'll become the issue," he said in the Sept. 29 debate, said voters didn't "deserve to know" his position or would know it "when the election is over,"

His media cheerleaders like CNN's Don Lemon said questions about court packing were just "hypothetical" -- a tautology, since any question about what a candidate would do is hypothetical, since it depends on who wins the election.

But on Monday, Oct. 9, Biden changed his tune. In an interview with WKRC Cincinnati, he said: "I'm not a fan of court packing. But I don't want to get off on that whole issue." Presumably, he noticed that packing the Supreme Court doesn't poll well: a Washington Examiner/YouGov poll showed 47% of voters opposed to expanding the number of Supreme Court justices and only 35% in favor.

More evidence of its unpopularity is that Democrats stopped using the term "court packing" -- in common use since Franklin Roosevelt called for adding up to six new justices in 1937, 83 years ago -- and started arguing that adding new justices would be "depoliticizing." George Orwell, call your office.

Biden's swerve is obviously unconvincing, and not just because he opposed court packing for years; he opposed government-paid abortions for decades, and then switched this cycle. "I'm not a fan of court packing," translated into English, means, "I'll pack the court if I get the votes." Which he might well: Polls show Biden well ahead and Democrats in shape to win a majority in the Senate. At which point, court packing could become one of the first orders of business.

Similarly, during the 2018 campaign, Democratic House candidates downplayed talk of impeachment, as my colleague Byron York notes. But once in office, these seemingly thoughtful moderates from upscale districts all dutifully voted for impeachment. Similarly, despite ominous polls, Speaker Nancy Pelosi squeezed out a majority for Obamacare in 2010. "Don't listen to what they say now," York tweets. "They'll do it if they can."

What would a packed Supreme Court, with four new seats giving Democratic-appointed justices a 7-6 majority (or 9-6 with six new seats), do? For a forecast, consider the recommendations of Harvard Law Professor Mark Tushnet, made back in May 2016 when he was looking forward to a Hillary Clinton presidency, which would have produced a 6-3 majority of Democratic-appointed justices.

Tushnet called for a "hard line" on "culture war" issues. He leaves little doubt he'd like a packed court to deny tax exemptions to churches which refuse to host same-sex marriages and to uphold banning of books attacking political candidates in the run-up to elections.

These are both positions that Obama administration lawyers told the Supreme Court would be serious possibilities after the Obergefell case legalizing same-sex marriage and after an overruling of Citizens United upholding corporations' free speech rights. The Heller decision upholding the "right to keep and bear arms" is a clear candidate for rollback.

Tushnet also calls for the summary overturning of the Casey precedent, which allows some state restrictions on abortions, and of Buckley v. Valeo, which said some campaign finance limitations violate the First Amendment. He would silently repeal part of the 1964 Civil Rights Act by fully embracing racial quotas and preferences in employment and education.

This doesn't exhaust the list of ways in which national policy could be permanently altered, over the objections of public opinion, by the activist liberal Supreme Court majority that's the goal of court packing advocates. The practical changes would be much greater than even an overturning of Roe v. Wade, which would leave in place laws allowing abortion in states where more than 80 percent of abortions have been taking place.

As a political issue, court packing has been dangerous not only for Biden but for Democratic Senate candidates. The Washington Examiner/YouGov poll shows that only 32% of independents favor court packing and only 30% of voters want a Supreme Court that is slightly, mostly or overwhelmingly liberal.

No wonder that Democratic Senate candidates, like Biden, have been scampering away from the issue, suggesting that they'd never support court packing while leaving them an excuse to do so.

So, there's an excellent chance President Biden and a Democratic Senate would violate longstanding norms by abolishing the filibuster and packing the Court: "The argument that we needed a Republican Congress to keep President Clinton in check is what helped Senate Republicans run 2 points ahead of Trump in 2016," writes Republican consultant Patrick Ruffini. Will a similar argument hold the Senate or the presidency for Republicans this year?