The dispute centres on a build-to-rent provision in the bipartisan 21st Century ROAD to Housing Act, passed by the Senate in March and now facing resistance in the House.
His concerns could strengthen House lawmakers in both parties seeking changes, complicating senators' push to pass the measure quickly without reopening negotiations.
The bill is a rare major housing package aimed at easing shortages and boosting homeownership before midterms, and its fate is also entangled with Senate Republicans' cryptocurrency agenda.
Can a housing bill solve affordability if it discourages the construction of new homes?
Are large investors the real cause of the housing crisis, or a convenient scapegoat?