Actually this goes back to before the founding of our system. Juries have the right to jury nullification, though it has been watered down somewhat lately. From Chief Justice John Jay in a 1794 SCOTUS decision: "It may not be amiss, here, Gentlemen, to remind you of the good old rule, that on questions of fact, it is the province of the jury, on questions of law, it is the province of the court to decide. But it must be observed that by the same law, which recognizes this reasonable distribution of jurisdiction, you have nevertheless a right to take upon yourselves to judge of both, and to determine the law as well as the fact in controversy. On this, and on every other occasion, however, we have no doubt, you will pay that respect, which is due to the opinion of the court: For, as on the one hand, it is presumed, that juries are the best judges of facts; it is, on the other hand, presumbable, that the court are the best judges of the law. But still both objects are lawfully, within your power of decision." Jurors who vote for lesser charges because they feel certain law's penalties are excessive are within their rights as a juror where a juror in fully fulfilling their duties can vote for lesser charges even if they think the defendant is guilty of the greater charges. Usually jurors having these rights isn't advertised as this goes back to the 1895 SCOTUS decision of Sparf v United States where SCOTUS ruled that judges didn't have to tell jurors they had these rights, but whether or not the juries are informed of these rights, it has been repeatedly upheld that jurors have these rights.
Reducio ad absurdum if a state passed a law that made jaywalking a capital offense, juries in that state would be within their legal rights of acquitting people of jaywalking even if they juries believe the state proved the accused broke the law.