Twenty-three years after retiring from The Tonight Show — and a decade after his death — Johnny Carson remains the most popular late-night TV host, and it’s not even close, according to results of a scientific poll released Tuesday. Carson, who hosted the NBC show from 1962-1992, was identified by 25 percent of Americans who were asked the open-ended question: “Who is your favorite late-night television talk show host of all time?” The Quinnipiac University Poll surveyed 2,105 Americans by telephone. Coming in second was David Letterman, who earned 13 percent of the vote, though the recently retired host was beat by “none,” which scored 14 percent of the vote. The Quinnipiac poll broke down the results into four different age groups, and Carson was such a dominant choice among older Americans that it more than made up for the fact that only 1 percent of people ages 18-29 called him their favorite host. In third place overall was Tonight Show host Jay Leno, with 7 percent.