you just described the case against allowing people to use cash. (you know, "folding money" as my grandparents called it)
Cash is anonymous, and is regulated only when it comes to transferring into or out of a bank (or if you try to import/export it overseas). By its very nature of being decentralized, cash cannot be regulated in any practical or meaningful way between two private parties, which is, in practice, effectively no different from the current crop of cryptocurrencies. The key difference is that ALL transactions in the Bitcoin protocol are public, and therefore Bitcoin is actually much less private than cash transactions.
If the senator truly wanted what he said he wanted, he would push to regulate or abolish the use of cash and demand electronic payments in all circumstances. It's more of a "problem" than bitcoin is. How often do you see huge stacks of millions or tens of millions of dollars in cash when there's some big cartel bust? None of that would be possible if cash was regulated and traceable. But no, it's Bitcoin that's the problem, according to this guy.