A statement is persuasive and credible either because it is directly self-evident or because it appears to be proved from other statements that are so.
A drunk driver is very dangerous. So is a drunk backseat driver if he's persuasive.
To be persuasive we must be believable; to be believable we must be credible; credible we must be truthful.
There is no meaningful or persuasive constitutional distinction between semiautomatic handguns and semiautomatic rifles.
Power is the most persuasive rhetoric.