Clearly, the Weimar Government did not completely ignore Hitler's actions as he was imprisoned for the Beer Hall Putsch. The government's attempts to limit the activities of Hitler and his party continued after that with various bans on things like the wearing SA uniforms and the banning of the Nazi Party at one point. However, there are a couple of things we must keep in mind. First, political violence was common in Germany at the time so Hitler was not noticeably worse than everyone else. Second and more importantly, Hitler and his ideas were quite popular among the German people and it would have been very difficult for the government to completely prevent him from being a part of the political scene in Germany at the time.
So, the government did not completely ignore him, but it could not deal with him as harshly as we might, in retrospect, wish it had.