HB 1491 mandates that each county in Texas must enter into agreements with United States Immigration and Customs Enforcement (ICE) under Section 287(g) of the Immigration and Nationality Act. This would authorize county officers and employees to enforce federal immigration laws. It allows the Texas Attorney General to seek injunctive relief against non-compliant counties and denies state grant funds to counties failing to meet these requirements following a judicial determination. The bill also empowers the Texas Comptroller to implement rules for consistent enforcement of the funding denial provision.