The 2020 election will be transformative like few in our history. It will end with the death of the Republican Party as we know it, leaving the survivors to begin the struggle to renew the party of Lincoln and make it relevant for our times. It will liberate the Democratic Party from the country’s suffocating polarization and allow it to use government to address the vast array of problems facing the nation.

From listening to the waves of fraught criticism that followed each of the Democratic debates so far, you would not think 2020 was such a juncture. Commentators worried that the candidates’ anti-business policies and over-the-top plans for government would drive away moderate voters. They watched the candidates excite the Democratic base at the expense of independent voters whom they believe long for a return to bipartisanship. The commentators were just as befuddled that the Democratic candidates were critical of President Barack Obama, who knew something about “electability.”

Yes, Mr. Obama won in 2012, but he was the first president since Woodrow Wilson to win a second term with fewer Electoral College votes and a smaller winning margin in the popular vote over his closest rival than in his first election. Of course, Mr. Obama was met by a Tea Party revolt that helped push many white working class voters away from the Democratic Party, but his administration’s rescue of the big banks, along with prolonged unemployment and lower or stagnant wages for the whole of his first term, meant that the Democratic base failed to turn out and defend him in election after election. As a result, Mr. Obama presided over the crash of the Democratic Party in 2010 and 2014 that gave the Republican Party control of Congress and total partisan control in just over half of the states.

The elites who mostly live in America’s dynamic metropolitan areas were satisfied with America’s economic progress after the financial crash, but overall it helped make Donald Trump electable. He understood how dissatisfied the country was with the status quo. So rather than asking voters which candidate is more “electable” or who has the best chance of defeating President Trump, we need to ask which leader best understands this tumultuous period. Which candidate has a theory of the case that pushes aside other interpretations and critiques?