Sens. Elizabeth Warren (Mass.) and Brian Schatz (Hawaii) are at odds over a provision targeting institutional investors in housing. WASHINGTON — Two top Senate Democrats clashed with each other Wednesday over a bipartisan bill designed to boost housing affordability, reflecting a simmering debate within the party between advocates for more housing construction and those seeking to ensure its profits don’t enrich private equity. The squabble between Sen. Brian Schatz (Hawaii) and Sen. Elizabeth