Why do Trump supporters excuse or ignore his blatant, provable lies?

The latest lie that has been called out is that a month ago he talked about how well he knew Whitaker, what a good man he is, etc. Yesterday he said he doesn’t know the man at all, has never spoke to him. Many have seen them together. This is not a white lie that is forgivable. Why do his supporters choose to ignore the lies? Would they forgive or ignore their spouses, SO for lying so blatantly like this?