Presidential candidates and other politicians cannot rely upon consensus to determine which path to take. But they do need to listen to what the people are saying.
Tulsi Gabbard is more than just a presidential candidate and a politician. There is no realistic expectation that the Democratic National Committee will rein her in for her campaign rhetoric. Likewise, there is zero possibility that Speaker of the House Nancy Pelosi cares what Congresswoman Gabbard says or does.
So if she were just a presidential candidate and a member of Congress, there would be no need for this concern over her extreme comments. But she is also a commissioned officer in Hawaii National Guard. That is a different matter altogether.