I can barely fathom that allowing this has even crossed browser developer's minds. This feature is just evil from the start and every browser feature, no matter how trivial or benign will eventually be abused.
Or better, the click would cast a vote for the candidate the developer prefers...
That's the problem, though. Motivated humans can weaponize anything. We spend too much time trying to stave off the impossible, instead of going after the abusers - which today often are the presumably legitimate businesses, as a lot of feature misuse became standard business practice.