Sen. Joe Manchin (D-W.Va.) forewarned in a radio interview Monday that he will not support a hike in the corporate tax rate from 21% to 28% as proposed in President Biden's infrastructure bill, adding that there are "six or seven other Democrats that feel very strongly about this.”

Why it matters: The tax hike is Biden's pitch on how to pay for the $2 trillion price tag on his American Jobs Plan. But pushback from moderates like Manchin could kill the bill, as a 50-50 split in the upper chamber has made every Democratic vote a must-have.

• Manchin said he thinks the corporate tax rate should have "never been below [25%]" and that he would be comfortable with that number.

Between the lines: Senate Minority Leader Mitch McConnell said last week that he will fight against Biden's plan, signaling that there will be no Republican support for the measure.

• And with the filibuster still in place, Democrats will also likely still need to pass the measure through a budget reconciliation process in order to avoid the need for 10 Republican votes, even if the entire Democratic caucus supports it.

What he's saying: "As the bill exists today, it needs to be changed. ... Bottom line is that's what legislation is all about. This bill will not be in the same form you've seen it introduced." Manchin said, adding that Biden's proposal might be broken up into three separate bills.