Attorney General Jeff Sessions is Democrats' nightmare

President-elect Trump's transition team knew that nominating Jeff Sessions for Attorney General would set off controversy. Democrats and their allies in the press have at key times in the past called Sessions a racist — they're now using the Alabama senator's full name, Jefferson Beauregard Sessions III, to heighten the Old South effect — and now, as they oppose Trump at nearly every turn, they've turned to race again.

Here's why the effort to stop Sessions is likely to intensify as his confirmation hearings near. Sessions is the Senate's highest-profile, most determined, and most knowledgeable opponent of comprehensive immigration reform. Democrats are particularly anxious about immigration because of the unusually tenuous nature of President Obama's policies on the issue. Those policies can be undone unilaterally, by the new president in some cases, and by the attorney general and head of homeland security in other cases. There's no need for congressional action — and no way for House or Senate Democrats to slow or stop it.

There are extensive, and in some cases, strict immigration laws on the books, passed by bipartisan majorities of Congress. Obama wanted Congress to change those laws. Congress declined. So Obama stopped enforcing provisions of the law that he did not like. A new administration could simply resume enforcement of the law — a move that by itself would bring a huge change to immigration practices in the United States. No congressional approval needed.

There are laws providing for the deportation of people who entered the U.S. illegally. Laws providing for the deportation of people who entered the U.S. illegally and later committed crimes. Laws for enforcing immigration compliance at the worksite. Laws for immigrants who have illegally overstayed their visas for coming to the United States. Laws requiring local governments to comply with federal immigration law. And more.

Many of those laws have been loosened or, in some cases, completely ignored by the Obama administration. A Trump administration would not need to ask Congress to pass any new laws to deal with illegal immigration. If there was a presidential order involved in Obama's non-enforcement, Trump could undo it, and if there were Justice Department directives involved, Sessions could undo them, and if there are Department of Homeland Security directives involved, the still-to-be-nominated secretary could undo them.