Can a law blog cover a few topics or just one topic? If a lawyer has two practices areas should they have two blogs?

I think you do want to focus on one niche. People want to know what you have to say about your subject.

I do not know that it is required to have two blogs if you have two practice areas, but to market effectively with one blog, the two practice areas would have to be very close. So if you were blogging on criminal defense and DWI, that is okay. If you are blogging on criminal defense and estate planning, that does not fit together well.