▁success , ▁however , ▁his ▁attitude ▁later ▁seemed ▁to ▁be ▁host ile ▁to ▁the ▁advance ▁of ▁opposition ▁parties , ▁instead ▁allowing ▁the ▁P RI ▁to ▁maintain ▁near - absolute ▁power ▁of ▁the ▁country ▁( at ▁the ▁time , ▁the ▁P RI ▁still ▁govern ed ▁all ▁of ▁the ▁Mexican ▁states ▁plus ▁the ▁Federal ▁District , ▁in ▁addition ▁to ▁holding ▁ 2 9 9 ▁of ▁the ▁ 4 0 0 ▁seats ▁in ▁the ▁Chamber ▁of ▁Deput ies ▁and ▁ 6 3 ▁of ▁the ▁ 6 4 ▁seats ▁in ▁the ▁Senate ). ▁However , ▁it ▁was ▁during ▁his ▁administration ▁that ▁the ▁opposition ▁National ▁Action ▁Party ▁( also ▁known ▁as ▁" P AN " ▁for ▁its ▁initial s ▁in ▁Spanish ) ▁started ▁to ▁become ▁popular ▁with ▁the ▁masses , ▁especially ▁in ▁Northern ▁Mexico . ▁ ▁In ▁ 1 9 8 3 , ▁during ▁the ▁municipal ▁elections ▁in ▁the ▁northern ▁state ▁of ▁Ch ih u ah ua , ▁the ▁P AN ▁won ▁the ▁state ' s ▁nine ▁biggest ▁Municipal ities , ▁which ▁held ▁ 7 0 % ▁of ▁its ▁population . ▁The ▁border ▁state ▁had ▁been ▁one ▁of ▁the ▁most ▁affected ▁by ▁the ▁government ' s ▁policies , ▁spe cially ▁the ▁national ization ▁of ▁the ▁Bank ▁decre ed ▁in ▁the ▁last ▁months ▁of ▁former ▁President ▁López ▁Port illo ' s ▁administration . ▁R ather ▁than ▁accepting ▁that ▁the ▁un pop ular ity ▁and ▁cor ruption ▁of ▁the ▁P RI ▁in ▁Ch ih u ah ua ▁had ▁led ▁to ▁such ▁a ▁defeat , ▁the ▁local ▁P RI ▁b oss