Yes, I think it's definitely a form letter. My guess is, it's not from this individual senator's office. I imagine it's boiler plate from a central Democratic Party communications office that all the Dems in the House and the Senate are using.

Funny thing is, in the 1980s one of my "specialties" was teaching/advising organizations how to write a form letter that could serve as a response to a wide range of complaints about a particular topic that nevertheless wouldn't sound like a bunch of blather that came out of a can. There was a real need for this after offices back then first became computerized and "mail merge" and other software made it possible for the first time ever to put individual addresses and salutations on form letters (and to simultaneously print out corresponding envelopes).

One of the main points of how to write form letters that didn't sound like canned BS was that you had to repeat back to the people who had written in the first place what their own original complaints were. Even if you weren't going to do as the letter writers wished, you had to acknowledge in your letter back to them what they said and make them think you understood their POV and could see that they had a point. This isn't really hard to do - but it does mean you have to start out actually reading all the mail your office/org gets, keep a log/count of what the various complaints are, see what the major complaints/beefs are, and consider and look into whether any of the specific complaints/points have any merit.

Nowadays the Dems aren't even trying to do this. They just regurgitate what they believe and how great they and their bills are. They don't seem to have any clue any more that they are supposed to represent the voters/populace. They're in government for themselves, for the rest of the establishment elites, and for the lobbyists who wine, dine & fund them.