As recently as a few weeks ago, national polling found that a plurality of Americans expected Donald Trump to win this year’s debates.

Some of the early evidence suggests he did not. CBS News reported overnight:

In the first presidential debate between President Trump and Democratic nominee Joe Biden, voters who watched Tuesday night say Biden won the debate…. Forty-eight percent say Biden won, while 41% think Trump was the winner. Biden’s margin here is not too different than his lead in national polls. Ten percent called the debate a tie.

The same data found that a plurality of the poll’s respondents thought better of Joe Biden after the debate, while a plurality thought worse of the incumbent president.

CNN also conducted debate polling:

Six in 10 debate watchers said former Vice President Joe Biden did the best job in Tuesday’s debate, and just 28% say President Donald Trump did, according a CNN Poll of debate watchers conducted by SSRS.

All of this should be approached with some caution. We know from previous cycles, for example, that public attitudes on the debates are often shaped by coverage and the discourse, and initial reactions don’t always capture sustained national impressions.

For that matter, post-debate reactions are often disconnected from election results: initial polling found Hillary Clinton winning each of her three 2016 debates, just as John Kerry excelled in each of his 2004 debates. Neither won the presidency.

But the fact remains that Trump is trailing in ways incumbent presidents rarely do, and last night’s event was a rare opportunity to narrow the gap. An impressive performance may have helped — but there’s no reason anyone should have seen his performance as impressive.