no, there are no rules to follow with free speech- any rules to free speech are censorship by another name. requiring that someone stay within the meets and bounds of a forum for discussion is the exemption to this (E.G. mandating that the topic of discussion must be about Hillary is acceptable, Not being allowed to call her an insufferable twat in that discussion is not acceptable).

These are the three tiers of speech:

The nice(Full Censorship): I dont think either candidate is acceptable.

The not so nice (partial censorship): I think both presidential nominees are the worst possible outcome for this country, they are both horrendous choices and anyone who votes for them is making a huge mistake.

The uncensored (no censorship): Trump is a swindler who will drive us into the largest economic depression we will ever see, and will likely be the unraveling of the free world (see why we will never survive a second great depression). Hillary is a raging idiot who will sooner see us in another war than fixing our own countries problems, and will open the floodgates for gender discrimination in our country again, her presidency will either lead to war, or another massive depression.

Do you see the difference between the three communicated messages? it is impossible to convey your feelings thoughts and ideas properly while censoring yourself.