We don't have free speech. We have never had free speech. What we have is a rule that says the government, generally, can't punish you for what you say - but even that is not absolute.
We live in a country that values individual freedoms - and chief among them is the ability to express yourself. When a tech company choses to limit speech on their platform, that is, itself, an expression of speech which is protected from government intrusion.
Now - we have identified various classes of people, for whom we specifically ensure they are protected from discrimination in many platforms. Right now - political affiliation is not one of those protected classes.
Now when a tech company makes a choice, or even a "mistake" as they allege here, that expression of ideas is not free from criticism from the public. And, If people want to get up in arms, and protest the company for regulating political speech - that is a natural consequence of voicing their "opinion."
What we don't want, is to start down the road of the government placing itself in the shoes of the "individual" and deciding what content is acceptable, or not. The foundation of this country is built on the premise that any such decision belongs to the individual (in almost all cases).