However, as soon as he came to power, he broke the promise of fiscal discipline and cutting spending and the first thing he did was passed a bill to burrow more than half a trillion Euros under the votes of old parliament even changing the constitution.
Also because of the firewall they have imposed to AfD, for him the only coalition partner was SPD( which is more of a left leaning party) and they formed a government and since then it has been internal conflicts to pass the important legislations to get the country back on track.
All these has worked as a boost for the AfD because people realised that apart from AfD the only other main right conservative party in Germany is CDU/CSU (which is the party of the chancellor) and voting for them hasn’t resulted in the change they voted in last election and now, they don’t have any other choice than voting for AfD because voting for the same old parties expecting a different result would be the definition of insanity.