Mr. Ronan Costello:

If an individual blocks another individual on Twitter, that person can no longer see the other person's profile and timelines and can no longer direct tweets at or send that person a direct message. If the person happens to be in a group direct message conversation, the person who has been blocked is ejected from the group conversation. Blocking on Twitter is a definitive way to cut ties with someone on the platform.

Muting is the low-friction way of controlling interaction with someone else on the platform. That may be what the Senator is referring to. If the Senator mutes someone, she will not see that person's content and timeline but if she navigates to the person's profile, she will see what he or she says about anything.