That depends on your definition of "en vogue", to start off with, and I suppose also your definition of communism. For clarity's sake I'm going to assume that by saying communism is stigmatized today in the United States you mean that very few Americans see a revolution to replace the current system of government with one committed to Marxist (and maybe Leninist) principles as likely or desirable. I wanted to specify this because you might see articles every now and then talking about polls measuring whether people's views of capitalism are more favorable than their views of socialism, or vice versa, and I think those metrics might lead one to believe that communist political beliefs are much more widespread in the US than is actually the case.

And if by 'en vogue' you mean to ask, was there ever a time when support for communism might have appeared to be approaching a majority? Either in terms of socialist candidates for political office or in terms of non-electoral organizing (general strikes, uprisings, armed revolution, etc)? And the short answer to that is no, but instead of just leaving it there I want to talk about what support for communism looked like in the early 20th century.

The first name to come to mind when discussing the heyday of American socialism is probably Eugene Debs, who was a founding member of the Industrial Workers of the World and ran for president four times on the Socialist Party ticket. His first campaign for president was in 1904, just three years after the Socialist Party was founded, and received 402,000 votes (3% of the popular vote) nationwide. That same year saw over 4,000 strikes take place across the country. Debs ran for president again in 1908, then again in 1912, where he notable received over 900,000 votes (6% of the popular vote). Around this time, the Socialist Party had about 100,000 dues-paying members, with 1200 of those members holding municipal offices across the country, and readership of socialist newspapers was easily over half a million, if not approaching one million.

Debs ran for president for the last time in 1920 (while serving a prison term), and once again received over 900,000 votes, although this time only 3% of the popular vote (the 19th Amendment increased the voting population significantly). To this day this is the best performance of a socialist or communist candidate in a US presidential election. However, after the First World War, support for the Socialist Party fell considerably due to its opposition to the war and crackdowns by the government. The Communist Party was also founded shortly after the First World War, and its membership quickly surpassed that of the Socialist Party, with many recent immigrants having come to the United States with their communist beliefs from Europe, although this posed challenges for organizing in the United States, as ethnic groups tended to at times be more concerned with their home country's communist party than with growing the American communist movement. Still, although the CPUSA failed to grow its membership in the 1920s as the SPUSA had done in the 1900s, a shift in emphasis from hardline-anticapitalism and international solidarity towards advocacy and organizing for local working class issues, such as unemployment, evictions, food insecurity, or racial justice, meant the CPUSA still held influence in several major cities, just without growing its membership.

So to quickly summarize and compare, in the first two decades of the 20th century the Socialist Party received between 3% and 6% of the popular vote in presidential elections, and work stoppages were occurring by the thousands every year. Communist candidates for president in 2016 received less than 0.1% of the popular vote and 2018 saw 20 work stoppages involving 485,000 workers.* There were 83,000 registered members of the Socialist Party in 1916 (out of a population of around 100 million), and today the largest socialist** organization in the United States is probably the Democratic Socialists of America at 66,000 (out of a population of 328 million). There were certainly plenty of Americans vehemently opposed to communism a hundred years ago, just as there are today, but at the same time, a hundred years ago the communist/socialist movement had a much broader appeal, received much more support relative to the US population, and (I'm speculating here) was a more organized and unified movement.

*My source for the number of 1904 strikes gives the total number of work stoppages, versus the Bureau of Labor Statistics giving the number of strikes in 2018 that involved more than 1000 workers. Obviously this is not a good comparison, but the BLS data only goes back to 1947. For a better comparison to the 2018 data, in 1947 there were 270 strikes involving 1.6 million workers

**although you asked about communism, not democratic socialism, and I suspect that only a very small number of DSA members would self-identify as communists.

Some of the books I referenced for this answer:

A People's History of the United States by Howard Zinn

Black Marxism: The Making of the Black Radical Tradition by Cedric Robinson

Making a New Deal: Industrial Workers in Chicago 1919-1939 by Lizbeth Cohen

The Origins of the Urban Crisis: Race and Inequality in Postwar Detroit by Thomas Sugrue