N.M. Const. art. X, § 10
A. A county that is less than one thousand five hundred square miles in area and has a population of three hundred thousand or more may become an urban county by the following procedure:
(3) within one year after the appointment of the charter commission, the proposed charter shall be submitted to the qualified voters of the county and, if adopted by a majority of those voting, the county shall become an urban county. If, at the election or any subsequent election, the proposed charter is not adopted, then, after at least one year has elapsed after the election, pursuant to this section another charter commission may be appointed and another proposed charter may be submitted to the qualified voters for approval or disapproval.
B. An urban county may exercise all legislative powers and perform all governmental functions not expressly denied by general law or charter and may exercise all powers granted to and shall be subject to all limitations placed on municipalities by Article 9, Section 12 of the constitution of New Mexico. This grant of powers shall not include the power to enact private or civil laws except as incident to the exercise of an independent municipal power, nor shall it include the power to provide for a penalty greater than the penalty provided for a misdemeanor. No tax imposed by the governing body of an urban county, except a tax authorized by general law, shall become effective until approved by a majority vote in the urban county.
C. A charter of an urban county shall only be amended in accordance with the provisions of the charter.
D. If the charter of an urban county provides for a governing body composed of members elected by districts, a member representing a district shall be a resident and elected by the registered qualified electors of that district.
E. The purpose of this section is to provide for maximum local self-government. A liberal construction shall be given to the powers of urban counties.
F. The provisions of this section shall be self-executing. (As added November 7, 2000; as amended November 4, 2014.)
Compiler's notes. — This section, which was proposed by S.J.R. No. 26 (Laws 1999), was adopted at the general election held November 7, 2000, by a vote of 261,323 for and 225,439 against.
The 2014 amendment, proposed by S.J.R. No. 22 (Laws 2014) and adopted at the general election held on November 4, 2014 by a vote of 251,584 for and 173,316 against, allows certain counties to become urban counties; clarified the majority vote needed to adopt a county charter; in Subsection A, after "square miles in area and has" deleted "at the time of this amendment"; in Subsection A, Paragraph (1), after "county commissioners shall", deleted "by January 1, 2001"; in Subsection A, Paragraph (3), in the first sentence, after "if adopted by a majority of those", deleted "voters" and added "voting"; and in Subsection B, in the first sentence, after "functions not expressly denied", deleted "to municipalities, counties or urban counties", after "may exercise all powers", added "granted to", and after "shall be subject to all the limitations", deleted "granted to" and added "placed on".
County's proposed "right to work" ordinance would likely exceed the scope of authority granted to the county by the legislature. — In general, a New Mexico county possesses only such powers as are expressly granted to it by the legislature, together with those necessarily implied to implement those express powers, and where the legislature has granted counties the authority to provide for the safety, preserve the health, promote the prosperity and improve the morals, order, comfort and convenience of its inhabitants, such a grant of authority does not encompass or include the authority to adopt an ordinance which regulates contracts between employees, employers, and unions, and therefore, where Sandoval county has proposed an ordinance that is intended to provide that no employee covered by the federal National Labor Relations Act need join or pay dues to a union, or refrain from joining a union, as a condition of employment, the proposed ordinance would exceed the scope of powers granted by the legislature. Sandoval County Right to Work Ordinance (1/18/18), Att'y Gen. Adv. Ltr. 2018-03.
Federal law preempts county's proposed "right to work" ordinance. — The federal National Labor Relations Act (NLRA) regulates private sector employment, governs matters of collective bargaining, and preempts, or precludes, state and other non-federal laws that attempt to regulate areas covered by the NLRA, and therefore, where Sandoval county has proposed an ordinance that is intended to provide that no employee covered by the federal NLRA need join or pay dues to a union, or refrain from joining a union, as a condition of employment, the proposed ordinance is preempted by the NLRA and is unenforceable. Sandoval County Right to Work Ordinance (1/18/18), Att'y Gen. Adv. Ltr. 2018-03.