1) Beats a dead horse 2) Drubs 3) Harps on 4) Presses to absurd lengths 1) Harpson 
belabors 1. Someone who explains, worries about, or works at (something) repeatedly or more than is necessary: 'The guy kept belaboring the point long after we had agreed on how to settle the issue.' 2. Anyone who assails persistently, as with scorn or ridicule: 'The book belabors the excess of immigrants who are working in agricultural areas of th...