Should voting be mandatory in the United States?

The First Amendment protects the right to speak. It also protects the right not to speak, and courts have said so repeatedly. A ballot is expression: it says something about what you believe, even when it says "none of these." Forcing a citizen to walk into a booth and make a mark under threat of a fine is compelled expression, full stop. Defenders say you could cast a blank ballot, which misses the point. The government would still be ordering you to participate in a ritual on pain of punishment. We don't fine people for skipping church, or for declining to sign a petition, because in a free country abstention is itself a statement. Low turnout already says something, loudly: that millions of Americans look at their choices and decline. If your response to that message is to make declining illegal, you have not fixed legitimacy. You have just made the silence harder to hear.