Two main reasons: Many of the immigrants brought their politics with them from the old country. Hundreds of thousands of East Europeans had fled persecution from Tsarist Russia and other autocratic regimes, and retained their strong political feelings. Second, within the United States, 1917 was the height of the sweatshop era. Working conditions in factories, clothing manufacturers, so on, were dreadful by modern standards. Workers could work seventy-hour workweeks for a few dollars with no access to insurance, credit, even bank accounts.

The rights of workers was the premier human rights issue of the era, and many immigrants had leading roles in the emerging labor movement.

Yes, he enjoyed the freedoms. As a journalist who had suffered censorship and/or harassment all across Europe — Austria, France, Spain — he had to enjoy the freedom he found working at Novy Mir in New York. But there were quirks all around him.

America, during those ten weeks he spent in New York, was going through rapid changes in its views on the war in Europe, testing that concept of freedom of speech, ultimately to the breaking point. Ironically, Trotsky was one of the people who tested it to its limits.

History was heading in that direction. What struck me, though, was the wonderful level of free expression that existed during those weeks immediately before the country entered the war — something that has never really existed since then in the same way.

America had no Department of Homeland Security, no CIA, no NSA. The FBI existed, but was still limited to chasing interstate prostitutes and car thieves. Trotsky himself took a public position, reported even in the New York Times, that if the country entered the war, socialists should engage in “mass actions” to stop it — literally trying to block the war effort physically.

Within a few weeks, this would be considered treason, and people would be arrested for far less.

We go through pendulum swings on this issue. After the war ended in late 1918, things never quite went back to normal. 1919 saw the first Red Scare and Palmer Raids. Even during the freewheeling “roaring twenties,” government agencies kept much closer watch on dissidents than before.

The county’s entry into World War II in 1941 saw yet another crackdown, followed by yet another Red Scare in the late 1940s and 1950s. With today’s focus on terrorism, it’s hard to see how we can ever get back to that earlier era. What I hoped to convey, however, is a sense of how much our new “normal” has in fact strayed from the earlier levels of freedom this country has enjoyed.

Trotsky saw the American socialists as split — not unlike the movement he experienced in Europe — and tried to radicalize the dissidents. The American Socialist Party had achieved a surprising level of success during that era: two elected Socialist members of Congress, dozens of mayors, state legislators, city councilmen, over 150 affiliated newspapers, not to mention its presidential candidate Eugene Debs receiving 6 percent if the popular vote in 1912 while running against the likes of Theodore Roosevelt, Woodrow Wilson, and William Howard Taft.

Trotsky saw [the American Socialist Party’s] leaders as compromised, “reformers” as opposed to “revolutionaries,” and had little faith in them. But he also saw the rank and file — like that energized, raucous crowd at Carnegie Hall — as strong and militant. His hope was to harness that energy and radicalize the party, which ultimately meant challenging the existing leadership: people like Morris Hillquit and the Forward editor Abraham Cahan.

World War I created a huge ideological crisis for socialists. Socialism was intended as an international movement. Workers in England, France, and Germany were supposed to identify as a united international working class against its common enemy, the capitalists.

But when war broke out in 1914, workers in these countries quickly got swept up in the patriotic fever and enlisted in armies to fight workers from the other countries — and socialist politicians in France, England, Germany, even Russia, led the movement. To Trotsky, Lenin, and other “internationalists,” this was a stark betrayal and created great distrust.

Since America had not yet entered the war in 1917, its Socialist leaders remained untested. Morris Hillquit, for instance, was staunchly antiwar, but also considered himself a patriotic American. The “anti-patriotic Socialists” at Trotsky’s dinner party in Brooklyn that night were very concerned that the party would lose its nerve when the crisis came.

The disagreement was over how far to push things if America actually entered the world war. Hillquit and the party leadership insisted that Socialists had to follow the law, a bedrock principle to them in trying to maintain their party within the American mainstream.

But to Trotsky, Fraina, and the dissidents (including, in this case, Eugene Debs himself), the war issue demanded a stronger response. They called for general strikes and street protests designed to physically interfere with war industries, troops movements, and conscription.

This, to Hillquit, threatened the existence of the Socialist Party itself. But Trotsky and Fraina considered Hillquit’s squeamishness an unacceptable compromise. This split — ultimately between American socialists and American communists — would live on through the next several decades.

By radicalizing and energizing the socialist left, Trotsky set the stage for a split that would have devastating effects. Within three years, by 1921, the socialist movement in America would be shattered — first by divisions between socialists and communists, then by a harsh government crackdown generally remembered as the 1919–1920 Palmer Raids, in which thousands would be arrested and hundreds deported.

By the late 1920s, membership in all the various communist and socialist parties in America combined would number barely ten thousand, compared with over one hundred thousand at the time of World War I. There would be resurgences, but the numbers would never approach the earlier era.

But Trotsky would always maintain his group of followers, and his ideology would adapt and become highly relevant to leftist national movements in the forties, fifties, and sixties. He retains an appeal even today as the historical alternative, holding out the possibility that even in Russia things could have worked better.

In the short term, yes. Hillquit’s insistence on electoral, legal politics failed to protect the Socialist Party during the wartime crackdowns of his era and the postwar Red Scares. And yes, he had his fingerprints on the expulsions of large numbers of members that weakened the party at a dangerous time.

But in the long run, I think his approach won out. His platform of “reforms” — a social safety net, government regulation of markets and workplaces, strong civil liberties, union recognition, social security, and the rest — was largely adopted and today is considered a staple of American life. And this year’s run by Bernie Sanders as a democratic socialist for president (an opportunity Hillquit would have loved) showed that socialism still has strong popular appeal once freed from the stigma of the Cold War.

One hopes that the movement will continue and vindicate the ideas of both these men.