Why? Because Trump wants a Bush-Obama immigration policy, that's why.
Remember when Trump made a big show of “canceling” TPS for several hundred thousand refugees in 2018?
Total scam - most of them can stay until after the 2020 election - and, all of them will get federally funded assistance to find out if they are eligible for permanent residence or more extensions under other federal programs.
You do realize it's been 30 yrs and counting since any president followed the law on immigration? They're all "holdovers". The last president to enforce immigration law was Eisenhower.