As President Donald Trump keeps a lower profile during his final weeks in office, behind the scenes the administration is racing to solidify his legacy, fulfill campaign promises and overhaul federal regulations that could take President-elect Joe Biden years to undo.

"I think that there will be a lot of things happening between now and the 20th of January, a lot of things," Trump asserted in an Oval Office appearance on Thanksgiving.

From immigration to environmental protections, the Trump administration is quietly pushing to finalize more than three dozen rule changes that could have significant impact for years.

"We call them 'midnight regulations.' It's the last chance to put these rules on the books before the Trump administration changes to the Biden administration," said ProPublica investigative reporter Isaac Arnsdorf who has created an online database tracking the pending regulations for the nonprofit news site. "They can be reversed, but not easily."