In terms of hard power/concrete power, a minority senator with no executive backing or judicial backing is severely limited. They must request records from executive branch departments. They have no enforcement arm. They have limited ability to limit legislation. They cannot pass recall legislation of any kind. They cannot exercise their legally granted authorities.

Your example about Bernie actually proves my point - he rallied the base and got the citizens to apply pressure. He took no concrete actions but used influence to rally support. This democrat party letter is the same thing at the same scope. AOC and Co traveling around to various town halls is that same thing. Every "too weak" statement they put out is the attempted use of influence and soft power. You're only happy about that from Bernie because you like Bernie. What's Bernie done to get Epstein files released? Is he "dirty" too? All he does is tweet about it and write letters and broadcast his message.

I'm left wondering if you genuinely think any US senator can go on their computer and open epstein_files.pdf any time they wish, and they're simply choosing not to do so. They literally passed a law to force the disclosure of the full files and the DoJ just said "nah". The lawsuit to attempt to force compliance is working its way through the courts, but Congress' only enforcement mechanism is recall legislation which requires a supermajority which they do not have.