Or you can accept that this is neither completely true nor necessary for success in politics, and as leaders, Senators have an obligation to use their access to greater amounts of information, and their ability to request any kind of study they want, to inform the public of the risks of what they want, and suggest ways to account for catastrophic damage while not leaving their constituents in the lurch economically.

Is that an idealistic scenario? Yes. But in that ideal, as in the now, the judgement of politicians matters, which means pointing out factors that bias their judgement is the duty of the media, both to inform the public and to keep these leaders in check.

You're blaming the media for this, but the real issue is that either out of fear of his constituents or the lack of sufficient information (which he can access quite easily) and a lack of leadership, Manchin is leaning towards voting for something that will benefit his constituents for the short term, at best, and most likely will harm them on net every year, and the nature of that harm is compounding as we proceed with the current status quo, so he's actively harming them.

You can be cynical about government and say this is how all politicians are. But if so, blaming the media for pointing out ways in which politicians do wrong merely makes your cynical assessment a self-fulfilling prophesy, because nothing then challenges these so-called leaders from their comfortable, thoughtless use of their political power to merely get themselves re-elected.