an unjust cause finds little support (idiom, from Mencius) / cf 得道多助[de2 dao4 duo1 zhu4] a just cause attracts much support
兰艾同焚
lán ài tóng fén
lit. to burn both fragrant orchids and stinking weeds (idiom) / fig. to destroy indiscriminately the noble and common / the rain falls on the just and unjust alike