Oh they do use facts and logic. It’s just that their facts are demonstrably false. All of their logical arguments begin by false premise. When you call them on either the false premise or their incorrect facts, then the ad hominem F bombs start flying.
When they start with the nonsensical insults, you know you have won the debate. Soon then the libs will start picking lint from each others navel and sniffing it in an attempt to determine who is the most astute socialist.