Today, I learned that the opposite of a straw man argument is a steel man argument.
Instead of engaging with the weakest point of your opponent’s argument you first summarize and then reinforce their basic point. Then you offer your side.
In other words, it’s building the best form of the other side’s argument and only then debating it. It’s being charitable and patching up the weaknesses in the other side’s position so that he can bring the best counter-argument to your point of view.
Imagine if political candidates employed this technique during televised debates. Say, having Joe Biden carefully summarize and bolster Bernie Sander’s Medicare for All (to Bernie’s satisfaction) and only then presenting the counterpoint. One can dream.