In-Person: Saturday before Election Day at the county clerk's office. 28 days before Election Day otherwise
By Mail: Postmarked 28 days before Election Day. However, an application may be accepted through the Friday following the deadline if the application is postmarked before the deadline.
Online: 28 days before Election Day.
New Mexico
Registration
Requirements
To register in New Mexico you must:
be a citizen of the United States
be a resident of the State of New Mexico
be 18 years of age at the time of the next election
not have been denied the right to vote by a court of law by reason of mental incapacity and, if I have been convicted of a felony, I have completed all conditions of probation or parole, served the entirety of a sentence or have been granted a pardon by the Governor.
Freedom is a fragile thing and is never more than one generation away from extinction. It is not ours by inheritance; it must be fought for and defended constantly by each generation, for it comes only once to a people. Those who have known freedom and then lost it have never known it again.
Ronald Reagan, 1911-2004 (Fortieth President of the United States)