Among the arguments being raised about why TFG won is the idea of "low-information voters": people who don't follow politics.
By this argument, your reason for deciding that a politician has your best interest at heart is that they tell you, and you hear them and believe them.
Here's a thought: what if politicians enacted policies that actually made these low-information voters' lives better? If they did that, they wouldn't have to _tell_ them anything. Actions speak louder than words.