A bipartisan duo — Republican Sen. Josh Hawley and Democratic Sen. Jeff Merkley — is teaming up on legislation that would ban large investment firms from snapping up single-family homes, a measure they say is aimed at the country's housing affordability crunch.The bill is set to be introduced on Thursday, two days after President Trump urged lawmakers in his State of the Union address to put limits on institutional investors buying houses. It will be the first new piece of proposed legislation on the issue since Mr. Trump's speech, though Merkley and over a dozen Democrats introduced a different bill on the same topic earlier this week.The legislation, known as the Homes for American Families Act, would amend the landmark Sherman Antitrust Act of 1890 to make it illegal for investment funds with over $150 million in assets to buy single-family homes, condominiums or townhouses. It doesn't apply to homebuilders that are constructing units for sale.…