▁the ▁House ▁of ▁Commons ▁for ▁the ▁district ▁of ▁Rou ville . ▁ ▁He ▁did ▁not ▁run ▁for ▁re - e lection ▁in ▁the ▁ 1 8 7 4 ▁election . ▁ ▁In ▁the ▁ 1 8 7 8 ▁election , ▁Mer cier ▁was ▁candidate ▁in ▁the ▁district ▁of ▁St . ▁Hy ac int he . ▁ ▁He ▁was ▁defeated ▁by ▁the ▁Louis ▁Tel lier , ▁his ▁Conserv ative ▁oppon ent . ▁ ▁Provin cial ▁politics ▁ ▁In ▁ 1 8 7 9 , ▁Mer cier ▁was ▁appointed ▁Sol ic itor ▁General ▁of ▁Quebec ▁in ▁the ▁Cab inet ▁of ▁Premier ▁Henri - G ust ave ▁J oly ▁de ▁Lot bin ière ▁and ▁served ▁in ▁that ▁position ▁for ▁less ▁than ▁a ▁year . ▁ ▁He ▁won ▁a ▁by - e lection ▁and ▁became ▁Member ▁of ▁the ▁Legisl ative ▁Assembly ▁for ▁the ▁district ▁of ▁Saint - Hy ac int he . ▁ ▁He ▁was ▁re - elect ed ▁in ▁the ▁ 1 8 8 1 ▁and ▁ 1 8 8 6 ▁elections ▁and ▁won ▁another ▁by - e lection ▁in ▁ 1 8 8 7 . ▁ ▁He ▁left ▁an ▁impact ▁on ▁a ▁later ▁leader , ▁Henri ▁Bour assa . ▁ ▁Party ▁leader ▁He ▁became ▁the ▁leader ▁of ▁the ▁PL Q ▁in ▁ 1 8 8 3 . ▁A ▁pract ising ▁lawyer , ▁from ▁ 1 8 8 5 ▁to ▁ 1 8 8 7 ▁he ▁was ▁President ▁of ▁the ▁Bar ▁of ▁Montreal . ▁He ▁strongly ▁opposed ▁the ▁execution ▁of ▁Louis ▁R iel ▁in ▁ 1