How do Arminians reconcile free will with God's omnipotence logically?

I just finished reading Mere Christianity and was blown away by some of the statements Lewis makes. He mentions "even [God] cannot produce [a changed heart] by a mere act of power …. It is something they can freely give Him or freely refuse Him ." (Mere Christianity Book 3 chapter 10) This brought up an interesting point in my mind: if you believe in the idea of Free Will with regards to Salvation or a changed heart, you indirectly believe that there is something God cannot do. This directly contradicts the scriptures including Matthew 19:26 and Luke 1:37 (as well as many others, see [OpenBible's *What Does the Bible Say About Omnipotence?*](https://www.openbible.info/topics/omnipotence)) that talk about Gods omnipotence. I grew up in a Calvary Chapel church where Free will was pushed ad nauseam and I was wondering how these Christians as well as other Arminians reconcile free will with something God cannot do.