The question the cases present transcends ideology. It is whether tech platforms have free speech rights to make editorial judgments. The most important First Amendment cases of the internet era, to be heard by the Supreme Court on Monday, may turn on a single question: Do platforms like Facebook, YouTube, TikTok and X most closely resemble newspapers or shopping centers or phone companies? The two cases arrive at the court garbed in politics, as they concern laws in Florida and Texas aimed at protecting conservative speech by forbidding leading social media sites from removing posts based on the views they...