The Bolsheviks were elected in multiparty elections to a plurality in the Supreme Soviet in 1917. The FSLN won elections including the 1984 presidential election which was judged free and fair by international observers. Elections have their place and some of the legitimacy of both these parties comes from their electoral victories.
But there are other times when force is rightly employed, in the service of the popular will. For example, the Bolsheviks outlawed one by one the various opposition parties as those parties went into open alliance with the White Army that was trying to destroy revolutionary Russia forever. The Sandinistas censored one issue of an opposition newspaper that called for terrorist attacks on the country. To take some American examples, opponents of the American revolution were tarred and feathered. Thomas Jefferson issued a writ of attainder and a Virginia judge had "lynch law" named after him for his lynchings of Tories. Lincoln suspended habeas corpus and censored the press and the mails. Of course, both of the American revolutions mentioned here also involved the direct violent subjugation of the minority by the majority.
If you want to act like elections and the "democratic process" based on a Constitution established via war are more important than substantive fairness and social justice, be advised that the right doesn't show the same scruples. From Aaron Burr's coup attempt, to KKK intimidation, to the theft of the New York mayoral election from Henry George, to kicking the elected Socialist Party members out of the New York state legislature, to the bankers' plot against Roosevelt, to the law outlawing the Communist Party at a time when it had several elected office holders, to the politically motivated Clinton impeachment, to Bush v. Gore and modern procedural barriers to substantive democracy, the right sees elections as a means to an end, not an end in itself. Would that the left were less muddle-headed.
Salvador Allende was democratically elected and never used unconstitutional force against his political enemies, so he was killed in a fascist coup. The Spanish Socialists put electoral victory and constitutional nicety ahead of the clear wishes of the Catalonian people as expressed in the streets, as well as the war effort against Franco, and Franco, who was untroubled by similar scruples, was able to take power.
I am very much a proponent of democracy. And to me, democracy means rule by the majority, that is, by the working class and the oppressed. But Democracy (as in Boss Tweed, Richard Daley, and Huey Long) means a cobbled-together coalition of people united by dissatisfaction with the Republicans but with no political perspective other than trying to convince the billionaires who make or break candidacies that they are better.