No, that is not how taxes work. You do not get to deduct a dollar from your tax obligation for every dollar you donate.

You only deduct the percentage dictated by your tax bracket. So assuming he's in the 39.6% tax bracket his tax obligation is reduced by 39.6 cents for every dollar he donates.

This is an oversimplification, there's a bit more to it than that, but you get the point. Maybe.