Here's a footnote from a paper I wrote about Sinclair Lewis last year in the spring:

Critic Mark Cantwell wrote of Lewis: "For although Lewis has written at least two first-rate novels, and created a dozen powerful characters, and produced a half-a-hundred masterly satirical sketches scattered throughout these books—as well as adding new words to the language and popularizing, more than anybody else, a new and skeptical slant on American life—he has also turned out as much journalistic rubbish as any good novelist has signed his name to, and he has written novels so shallow and dull they would have wrecked any reputation except his own" (111).

Lewis' literary reputation suffered a great blow at the hands of Mark Schorer, his hatchetman "biographer," who clearly disliked Lewis and spent 800+ pages to tell us why he thought Lewis was such a bad writer. Another of my footnotes:

One can only wonder at the scholarly goals of Lewis biographer Mark Schorer (Sinclair Lewis: An American Life, 1961). He is widely quoted from his 867 page study: "He was one of the worst writers in modern American literature, but without his writing one cannot imagine modern American literature." (813)

Schorer didn't recognize the work that Sinclair Lewis was asking some of his characters to do, and that in some of the instances of extremely two-dimensional characters, he had a greater goal than character development. He was a social writer, who by the time he finished with Main Street and Babbitt, his uncanny ability to state the obvious took him from revolutionary to invisible within a very few years. The obvious became, well, so obvious that it wasn't remarkable any more.
--SRS