Representative Yarmouth, the chairman of the house budget committee, has clearly explained that the spending Manchin is objecting to is not a burden, even without a tax increase. He understands the mechanics of federal finance and monetary policy, but the old "gold standard" thinking much better suits the status quo donor class Manchin (along with many others of both parties) is beholding to and actually a member of.
We should tax the wealthy much more, but spending on the public purpose should not be dependent upon that, and isn't in reality. If we claim we depend upon that ability we deny one of the major tools Congress was given to manage the economy, the power of the purse. We are also admitting that we must maintain the ability of the wealthy to remain wealthy enough to fund our government and its programs.
The best way to see that the wealthy pay their "fair share" is to make them irrelevant to the federal budget process. That starts with educating the voters about the process, which neither party has attempted for fear of upsetting their donors who use our lousy economy to control labor demands. The myths of the gold standard era are all that stands between us and the many benefits other, far less productive, countries take for granted.