Congress just passed the most significant housing bill in decades, so why won’t Trump sign it?

A sprawling legislative package aimed at lowering the cost of housing and spurring more home construction won bipartisan approval from Congress this week, but it’s hit a major roadblock in becoming law: President Donald Trump.

The White House supported the 21st Century ROAD to Housing Act, but on Wednesday Trump canceled the signing ceremony for the bill, saying he would not sign the measure until Congress passes legislation that would require proof of citizenship for all voters.

Here’s what to know.

How significant is this housing legislation?

The measure is the culmination of months of negotiations by lawmakers who combined dozens of bills meant to address how housing affordability for both renters and aspiring homeowners in the U.S. has grown increasingly out of reach for many Americans.

The bill would reduce federal regulations, streamline environmental reviews, speed up the constru...