Post debate autopsy - polls (CSPAN, CNN) and two focus groups have thoughts on the debate:

 CSPAN had an online poll showing that Donald Trump won the debate by an amazing 35 points! 

And CNN reports that AFTER the debate when asked who they trust more on the economy, Donald Trump's numbers went up by two - while Kamala Harris's went down by two points for a 20 point lead on the most important issue for voters - the economy.

CNN focus group doesn't go as planned

Finally Reuters interviewed 10 undecided voters.  Six moved to Trump and three moved to Harris:

Reuters interviewed 10 people who were still unsure how they were going to vote in the Nov. 5 election before they watched the debate. Six said afterward they would now either vote for Trump or were leaning toward backing him. Three said they would now back Harris and one was still unsure how he would vote.

Although the sample size was small, the responses suggested Harris might need to provide more detailed policy proposals to win over voters who have yet to make up their minds.

Five said they found Harris vague during the more than 90-minute debate on how she would improve the U.S. economy and deal with the high cost of living, a top concern for voters.