Before the pandemic, the economy was the single strongest asset Trump had to persuade people — especially those who are repelled by his behavior — to give him a second term. Unemployment was at historic lows. The stock market was at record highs. The economic growth rate, while not spectacular, was steadily positive.

The economy’s collapse, as businesses shut down as part of the efforts to combat the covid-19 pandemic, robbed Trump of the ability to credibly argue his case. Today his campaign message is a combination of hope — claiming the economy is already roaring back in the face of numbers that suggest otherwise — and the argument that he will be more effective than Biden in the rebuilding. More Americans still trust him over Biden on the economy, but the margin is not what it was.

The second advantage that Trump once enjoyed was in the luxury of time to prepare for the general election and to define his opponent. Other incumbents have used this tactic effectively. In 2012, just as the Republican nomination contest had concluded, the campaign of then-President Barack Obama unleashed a barrage of television ads designed to define challenger Mitt Romney as an out-of-touch plutocrat. In 2004, George W. Bush’s campaign clobbered Democrat John F. Kerry just he was coming out of his primary. Bill Clinton’s reelection campaign put Republican Bob Dole on the defensive early in the 1996 campaign, and Dole never recovered.

Biden effectively became the Democratic nominee in early March. Like Romney in 2012, he had limited resources and his campaign was far from ready for a full-fledged general election contest. But Biden proved to be an elusive target. The Trump campaign tried and tried to find something that would stick, but as spring turned to summer and as June bled into the late-August conventions, little damage was done.