Manchin, like a great majority of Democrats, is a neoliberal market worshiper. If Biden wasn't closer to him than he is to Bernie in ideology there would have been much more pushback for his obstruction.

One of Manchin's main "stated" objections is the threat of inflation with so much new money in circulation, even though the bill was neutral in terms of deficit creation (note I didn't say "paid for"). Manchin had no qualms in voting for the defense budget increase and he knows very well that will never be "paid for". Actually, none of ever gets paid for because our government doesn't use, or need, revenue to fund spending. We simply keep a running tally of the difference between what is created via federal spending and what is collected via taxation.

That difference is the net "earning" of the private sector from its commerce with our government. We call that the deficit when we talk about yearly accounting and the national debt when we aggregate it since our nation's founding. As such, it represents our net money supply that is required to retire private sector debt or be net saved.

All of the deficit hawks in Congress know how this works, but they don't want us to know it or we might actually demand nice things, such as child care, single payer healthcare, etc., like other countries have and take for granted as a right. Any suffering in this rich economy is entirely a "political decision" made by someone, or some group, that "wants" it to continue because they benefit from it. It certainly isn't "economics", as that was debunked as long ago as '46 by a New York Fed Chairman.