Ohhh boy, deputies cared a *lot*. If you can read french:
http://gallica.bnf.fr/ark:/12148/bpt6k6427233z.r=debats parlementaire deputeTonkin Tonkin?rk=257512;0
This is the transcript of the parliamentary record (Journal officiel de la République française, Débats parlementaires, Chambre des députés) for the March 30th, 1885. It really is one of the most dramatic parliamentary transcripts I've ever read, after the miscalculated telegram from one of the generals sent to France, demanding
immediate reinforcement and supposedly precarious condition they were in (Lang Son Telegram), the Opportunist Republican government led by Jules Ferry collapsed on this day, with Jules Ferry's motion to increase the military credit for the War in Tonkin failed.
It includes juicy bits like Georges Périn, a supporter of Clemenceau, telling Ferry to "Don't keep on exploiting the honor of our flag! You’ve wrapped yourself in our flag for too long! Enough!" and Clemenceau accusing Ferry and his entire cabinet of high treason. Both extreme-left and right were against expansion in Tonkin for their own reason, and support was rather tenuous. If there was a real disaster, Qing could have definitely got away with significantly less concession to the French. On the election of 1885, I doubt it would have been enough to collapse Republican majority. It'd have impacted Opportunist Republicans, but I'm not sure if it votes would have gone to the right. I imagine it would have strengthened broad Radical-left and Radical-Socialists than monarchists. It'd certainly discourage further colonial expansion for quite awhile. Since OTL Tonkin affair already had such effects.