The bill, ushered through Congress by Republican leadership and signed by Trump Friday, includes $4.5 trillion in tax cuts, slashes spending on Medicaid, and creates temporary tax deductions for overtime and tipped income. It includes $170 billion for immigrant detention and for new personnel for Immigration and Customs Enforcement.

The massive bill is guided by spending requests from the White House. It will extend the 2017 Trump tax cuts, while cutting billions of dollars in social program funding. It’s been described as the largest cuts to social welfare programs since at least the 1990s, and according to some experts the most severe in modern history.