Being present in the U.S. without legal documentation is a civil violation, not a criminal offense according to the
American Immigration Council. While it's not a crime to simply be in the country without authorization, entering or reentering the U.S. without permission is a federal misdemeanor.
While there is no penalty for being present in the US without documentation you will probably be charge with Unlawful Presence, a civil offense with the primary consequence being deportation.
Probably the major difference in immigration enforcement under Trump versus previous presidents is that the Trump administration does not consider extenuating circumstances such as unable to locate documentation, meeting the legal requirements to stay in the country, your kid is in the hospital dying of cancer, etc...
Of course if you have a 5 million dollar Trump card or a genuine Trump red hat, that's all the documentation you will need.