Did the Emperor Constantine ever present explanations for putting off his baptism? The Emperor Constantine who favored Christianity as early as 312, and convened the Council of Nicæa in 325, postponed baptism till 337. Did he provide any reasons for doing so?
I do not think anyone knows as there is huge speculation on the subject.

Basically some see it as his cowardice to confess his faith, others see it as a prudent measure to keep his influence of power until the risk of his own execution for becoming a Christian had passed. He himself does not seem to say. I do not even believe we can prove He was a Christian. Maybe he was? God only knows.

It does seem though the God used Him to end so much Christian persecution, and it does seem that in some ways, at least initially, Christ overthrew the Gentile world by turning his heart in favor of His people. Quite soon after his death, Christ's kingdom grew like a mustard seed.