Shutting down a government might seem like power, but that was more a power move, a "result" that came in response to an action. The real proof of power is the impact that the action produced. What sustainable positive change benefiting his constituents did shutting down the govt produce? Ted Cruz's move might have had an impact in the end (you didn't say what that was), but simply doing something "big" doesn't reflect power. Power is about having an impact that delivers lasting benefits.
Take Corey Booker: him speaking on the Senate floor for over 24 hrs non-stop might seem like a display of power, but ionno if it accomplished anything. Bennie Thompson led the January 6 Committee. Seemed like power. We give him credit for doing something, yes. But what impact did it produce? For Cruz, Booker, and Thompson, having voters backing them up in numbers, being the deciding vote that you can use as a bargaining chip, or being the key for moving legislation, these are the strengths that reflect power. My whole point is that lawmakers who have substantial blocks of reliable, active voters backing them up is what provides them with power. You can hold the CBC accountable all you want, but they are not able to deliver, they are not able to wield the kind of power in the legislature that makes a difference as it stands now. We have the numbers (in the millions) that would make a difference nationally, but we don't use what we have.