 Complete the following phrase:  The Second Federal Republic of Mexico  is the name given to the second attempt to achieve a federalist government in Mexico after a period of centralism. Officially called the United Mexican States , a federal republic was established again on August 22, 1846 when interim president José Mariano Salas issued a decree restoring the 1824 constitution. The Second Republic continued to be rocked by the political instability that had characterized Mexico since 