What convinces is conviction. Believe in the argument you're advancing. If you don't you're as good as dead. The other person will sense that something isn't there, and no chain of reasoning, no matter how logical or elegant or brilliant, will win your case for you.
“The hope and change the Democrats had in mind was nothing more than a retread of the failed and discredited socialist policies that have been the enemy of freedom for centuries all over the world. I fear America is teetering towards tyranny.”