Jeremiah describes the course that the people have taken as evil and their might is not right.
In the context of the whole section, Jeremiah probably has mainly the prophets in mind here. They have abused their position of power to lead the people into evil ways instead of into faithfulness to the Lord.1
10 For the land is full of adulterers; because of the curse the land mourns, and the pastures of the wilderness are dried up. Their course is evil, and their might is not right.