Biden’s Tax Plan to Fund Spending Boom Stirs Democrats’ Unease

President Joe Biden’s planned tax code overhaul to offset trillions in new spending wouldn’t necessarily have an easy path if the administration moves on from bipartisan negotiations and opts to advance legislation with only Democratic support.

Biden has offered to pursue a narrower infrastructure package of around $1 trillion, paid for by a 15% corporate minimum tax and a better funded, more-aggressive IRS. But with Congress soon returning from its week-long Memorial Day recess, pressure is ratcheting up for Democrats to move on their own if there isn’t a bipartisan breakthrough soon.

“I don’t think we should run the risk ...