Born in the Austrian Empire (present-day Romania), Berger immigrated to the United States as a young man and became an important and influential socialist journalist in Wisconsin.

In 1919, Berger was convicted of violating the Espionage Act of 1917 for publicizing his anti-interventionist views and as a result was denied the seat to which he had been twice elected in the House of Representatives.

[14] The couple raised two daughters, Doris (who later went on to write television shows such as General Hospital, with her husband Frank) and Elsa, speaking only German in the home.

Jailed for six months for violating a federal anti-strike injunction in the 1894 strike of the American Railway Union, Debs turned to reading: Books and pamphlets and letters from socialists came by every mail and I began to read and think and dissect the anatomy of the system in which workingmen, however organized, could be shattered and battered and splintered on a single stroke [...] It was at this time, when the first glimmerings of socialism were beginning to penetrate, that Victor L. Berger — and I have loved him ever since — came to Woodstock [prison], as if a providential instrument, and delivered the first impassioned message of socialism I had ever heard — the very first to set the wires humming in my system.

As a souvenir of that visit there is in my library a volume of Capital by Karl Marx, inscribed with the compliments of Victor L. Berger, which I cherish as a token of priceless value.

[18] His ideological sparring partner and comrade Morris Hillquit later recalled of Berger that He was sublimely egotistical, but somehow his egotism did not smack of conceit and was not offensive.

Berger was regarded as one of the party's leading revisionist Marxists, an advocate of the trade union-oriented and incremental politics of Eduard Bernstein.

[21][22] Berger was terrified of Asian immigrants, who he believed would out-reproduce white Americans and further complicate the socialist movement's cross-racial solidarity.

[24] Instead, Berger argued that segregation was a symptom of an elite capture that left the American legal system indifferent to the poor of every race.

In Congress, he focused on issues related to the District of Columbia and also more radical proposals, including eliminating the President's veto, abolishing the Senate,[26] and the social takeover of major industries.

Berger was especially involved in the biggest party controversy of the pre-war years, the fight between the SP's centrist "regular" bloc against the syndicalist left wing over the issue of "sabotage".

"[28] The debate was vitriolic, with Berger, somewhat unsurprisingly, stating the matter in its most bellicose form:[29] Comrades, the trouble with our party is that we have men in our councils who claim to be in favor of political action when they are not.

We have a number of men who use our political organization — our Socialist Party — as a cloak for what they call direct action, for IWW-ism, sabotage and syndicalism.

I am ready to go back to Milwaukee and appeal to the Socialists all over the country to cut this cancer out of our organization.The regulars won the day handily at the Indianapolis convention of 1912, with a successful recall of IWW leader "Big Bill" Haywood from the SP's National Executive Committee and an exodus of disaffected left wingers following shortly thereafter.

The remaining radicals in the party remembered bitterly Berger's role in this affair and the ill feelings continued to fester until erupting anew at the end of the decade.

His newspaper, the Milwaukee Leader, had printed a number of anti-war articles, leading the postal service to revoke the paper's second-class mail privileges.

Despite these circumstances, Berger won 26% of the vote statewide in an April special election to fill a Senate vacancy, including winning 11 counties, in a three-way race.

[31] Berger's conviction was appealed and was ultimately overturned by the US Supreme Court on January 31, 1921, which found that Landis had improperly presided over the case after the filing of an affidavit of prejudice.

The seat remained vacant until January 1921, after his previous electoral opponent, Republican William H. Stafford, once again prevailed over Berger in the 1920 general election.

[36] According to historian Sally Miller:[37] Berger's papers are housed at the Wisconsin Historical Society, with smaller numbers of items dispersed to other locations.

[40]: 108  This publication included Berger's phrase regarding draining the swamp in reference to his assertion that the economic crises such as the Panic of 1893, were "hastened' by excessive profits—the $900,000,000 to Standard Oil "magnates".