The simple explanation is because the black
guy couldn't get it done.
WASHINGTON ― House Minority Leader Nancy Pelosi (D-Calif.) said Thursday that President Donald Trump told her on two occasions that he supports and would sign a bill to give legal status to young undocumented immigrants who came to the U.S. as children.
“We made it very clear in the course of the conversation that the priority was to pass the Dream Act,” Pelosi said at a press briefing. “Obviously it has to be bipartisan. The president supports that, he would sign it. But we have to get it passed.”
But, hey, if Trump can, why doesn't matter much...