Can a woman beat Mr. Trump?

Women have driven Democrats’ electoral victories, but many Democratic voters are nevertheless convinced a woman can’t beat Mr. Trump. Story after story documents Democratic voters — men and women alike — expressing the view that a woman can’t win. This may explain the lackluster to poor results so far for Senator Elizabeth Warren of Massachusetts. Yet by multiple measures, she is broadly liked by Democratic voters, second only to Mr. Biden in the Economist’s measure of who voters are considering. Her marquee policy position, a two-percent tax on wealth over $50 million, polls at 63 percent, including 55 percent support from independents and 57 percent support from Republicans.

Women have powered the resistance to Mr. Trump: The Women’s March was likely the biggest protest event in American history, and increased support from women drove a “blue wave” in the 2018 midterms. And in many elections, women candidates outperformed men: Among Democrats, “female candidates in 2018 are more likely to defeat male candidates than the other way around,” reports Ella Nilsen of Vox.

Mike Bloomberg’s money can buy a lot, but probably not the nomination.

Big business loves politics because sums that amount to pocket change in major industries buy big influence in Washington. Mr. Bloomberg is investing unheard-of sums in his race — he has more staff members than any other campaign, and his ads are everywhere. That spending has quickly elevated his poll numbers.

But there can be diminishing returns on spending: In 2016, Hillary Clinton outraised Mr. Trump three-to-one — and lost. Mr. Bloomberg’s record is dicey: He spoke at the 2004 Republican convention, praising George W. Bush and his war on terrorism. His “stop and frisk” regime was so brutal and discriminatory, it was struck down by a federal court as violating its victims’ civil rights. His presence supercharges the message from Mr. Sanders and Ms. Warren that billionaires are buying our democracy. He could win enough delegates to be a player at a contested convention, but it’s unlikely he can win a majority — and if the Democratic Party gave the nomination to a billionaire who supported Mr. Bush, it might as well shoot a big chunk of the Democratic electorate into space and hand Mr. Trump his re-election.

Black voters are the backbone of the Democratic Party, but …

So far, white voters have discounted their views. Former Mayor Pete Buttigieg of South Bend, Ind., and Senator Amy Klobuchar of Minnesota are flatlining with black voters, polling at 4 percent and 0 percent, respectively, in the latest Quinnipiac poll. Their records are troubling. Mr. Buttigieg oversaw a sharp decline in the number of black police officers, pushed out both the black police chief and fire chief, and his handling of the shooting of a black man by a police officer prompted anger and outrage among black residents. For her part, a case Ms. Klobuchar cited as an example of her tough-on-crime approach during her tenure as a county prosecutor might have resulted in the wrongful conviction of a black teenager. Sunny Hostin, a former prosecutor and co-host of the “The View,” called the case “one of the most flawed investigations and prosecutions that I think I have ever seen.” But both have been propelled forward because white voters have made up nearly all of the votes cast so far.

There are other mysteries.

Turnout is down, based on Iowa — except that it might also be up, based on New Hampshire. More moderate candidates are more electable, based on a study of congressional candidates — except that the leftier candidate might also be more electable, judging by Barack Obama’s dominant win in 2008 after beating Hillary Clinton for the nomination. Twitter is not real life, based on the composition of the Democratic electorate — except when it is, foretelling Mr. Biden’s fall and Mr. Sanders’s rise. There are two lanes, progressive and moderate — except when there aren’t, as Ms. Klobuchar’s surge in New Hampshire took voters away from both Ms. Warren and Mr. Biden.

One thing we do know for sure.

The last time Democrats unseated a Republican incumbent was in 1992, when we nominated the guy who had to go on “60 Minutes” during the primary season to deny credible allegations of infidelity and who did not win a single state until Super Tuesday. President Bill Clinton went on to win 370 electoral votes. And the last time we won the popular majority was when we nominated the black man who had admitted to using cocaine, who was caught on tape calling working-class whites “bitter” people who “cling to guns and religion,” and who sat in the pews with a pastor who declared, “God damn America.” Mr. Obama went on to win 365 electoral votes, carrying states like Indiana.