It is not illegal to, earn about the truth, nor its not illegal for voters to be told about the truth on their candidates. To the contrary, its our duty to learn the most we can, and its the duty of the opposing candidate to inform the voters about thier opponet such as Hillary who was not forthcoming on the truth., this is our right to know...
If Trump was paid to disseminate propaganda by Russians, or paid in return return for favors, or conspired to publicly slander, that would be illegal, like Hillary had done, but that's not what we have here... freedom of assembly for learning the truth with the intent of exercising free speech is our constitutional right.
It is not illegal to, LEARN about the truth