Only an act of God can stop Biden from getting the Democratic nomination. Photo: Ronen Tivony / Echoes Wire/Barcroft Media via Getty Images

﻿Most weeks, New York Magazine writer-at-large Frank Rich speaks with contributor Alex Carp about the biggest stories in politics and culture. Today, what the fallout from Super Tuesday means for Democrats — and for Republicans.

With Joe Biden’s victory in the South Carolina primary and his showing on Super Tuesday, the Democratic field has collapsed into a two-person race. How does that change what this primary means for Democrats, and for the GOP?

So many 2020 assumptions, including my own, have been upended since the South Carolina results came in last Saturday that it’s not easy to pick the most significant. But if I had to pick one, it would not be that Biden showed you can triumph without money or a “ground game,” or that a $500 million-plus outlay could buy Mike Bloomberg nothing more than a 72-vote victory over Tulsi Gabbard in American Samoa. It would be this: Democrats and Republicans alike underestimated the independence and power of African-American voters.

Now that their clout is self-evident, we are in for a reelection campaign in which a white nationalist president and his white nationalist party are going to accelerate their efforts to both suppress black votes and fan racist rage to whip up the MAGA base. The GOP has conclusive proof that an energized turnout of black voters not only jeopardizes a repeat of Trump’s frail 2016 victories in the Rust Belt but poses a threat in demographically transitioning red states like Texas, Georgia, and North Carolina.

Biden remains the weak candidate he’s been from the start — the same aging and erratic guy whom I, like so many others, have pronounced dead throughout the primary. He has plenty of baggage in his long political history, from Anita Hill to the Iraq War to his shilling for Delaware’s vampiric credit-card industry. His performance on the stump and in debates can be alarming; even in his exultant victory speech on Tuesday night he began by confusing his wife and sister. But barring an act of God, it’s hard to imagine Bernie Sanders catching up to him. You cannot win the Democratic nomination — and in my view should not win it — if you cannot win African-American votes. The failure to do so in commanding numbers is the coup de grâce likely to doom Sanders as it did Pete Buttigieg, Amy Klobuchar, Elizabeth Warren, and Bloomberg. A new Sanders ad with footage of him palling around with Barack Obama will not turn the tide.

This would have been readily apparent earlier if the Democrats hadn’t persisted in front-loading the primary with the lily-white electorates of Iowa and New Hampshire. The persistent assumption that black voters in South Carolina would be swayed by white Democrats’ verdict in Iowa — commonly held since Obama’s 2008 Iowa victory ostensibly had that domino effect — proved to be 100 percent wrong. Jim Clyburn’s endorsement meant something in South Carolina, not the choices of white Iowans who couldn’t even run their caucuses competently. The derisive view of Biden by most liberal pundits, myself included, meant nothing either. Klobuchar and Warren — the two presidential candidates endorsed by the nation’s most influential liberal news organ, the Times — failed to place higher than third in any of the states to vote thus far, their home states included.

As someone who regards Trump as an existential threat to America, I have no problem voting for Biden, a decent man who would preside over a caretaker administration that may be indistinguishable from Obama’s. He seems to have won the electability argument, wildly increasing turnout in suburban districts where Trump is highly vulnerable even as Sanders has failed to run up the numbers for his promised youth surge. What gives me some hope about Biden’s prospects for victory in November — desperate as it sounds, and is — is that Trump is far more erratic. It’s hilarious to hear Trumpists mock Biden for speaking of “Super Thursday” when Trump can’t correctly cite the name of the most immediate threat to the country, the coronavirus. Or to watch Republicans in the Senate reboot their inquiry into Hunter Biden even as Trump and his family rake in profits from the most kleptocratic administration in American history.

The fact that Trump and his partisans are reverting to their Hunter Biden strategy is an indication that Joe Biden’s comeback has made them anxious. Hunter Biden is a spent 2019 political piñata. It’s hard to imagine that at this late point, after an extensive impeachment drama exhausted public interest in all things Ukraine, that anyone is going to get worked up about Burisma now except the Fox News base that’s still clinging to Hillary Clinton’s email server.

There are other signs as well that Republicans are frightened by Biden and alarmed, as Trump manifestly is, by the prospect that their favored opponent, Sanders, may not make it after all. Useful portents, as always, can be found by a close monitoring of Rupert Murdoch’s orbit. On the day before South Carolina, his Wall Street Journal ran both a news story and an op-ed piece promoting the notion — implicitly racist as well as fanciful — that Tom Steyer’s money could buy off black voters and sink Biden. Once that theory failed, we’ve seen Murdoch-Trump lapdogs yapping in circles. In The Federalist, the Fox News contributor Mollie Hemingway wrote of Biden’s “apparent senility” while touting Sanders as the Democrats’ “one candidate with energy and excitement.” In the New York Post, the reliable tool Michael Goodwin argued that Biden’s platform “would be the party’s most radical since George McGovern” in 1972. “We know how that election ended,” he concluded, as if there were a prospect under any scenario that the Republicans could win this year by any margin approaching a 49-state landslide.

It’s the racial moves to come that will be both cunning and vicious. As Thomas B. Edsall documented in the Times this week, that $11 million Super Bowl ad featuring a 64-year-old African-American woman granted early prison release by Trump was just the kickoff of an elaborate GOP campaign. The goal is to peel off black voters or, failing that unlikely result, to make some African-Americans and white suburbanites feel less alarmed by Trump and less inclined to turn out to vote against him. In the push to disempower and disenfranchise African-Americans, the Trump campaign will be aided by Russia as it was in 2016, and by the castration of the Voting Rights Act by the John Roberts Supreme Court, whose grotesque legacy could be seen in the long lines at polls in black-majority districts on Super Tuesday. And I can’t entirely dismiss the months-long speculation that Trump might dump Mike Pence in favor of Nikki Haley if he thinks that move will somehow lull gullible suburban and African-American voters into believing that his nativist America First movement is benign rather than fueled by white supremacy.

If we’ve learned anything, it’s fruitless to forecast an outcome. With two unpredictable septuagenarian candidates, a viral health threat that the White House is addressing mainly as a public-relations nuisance, and a gyrating economy, anything can happen and — as we now know more than ever — will.