Probably should be Leif Erikson Day since he beat CC to America.
No, because Erikson didn't spark significant colonization to America.
On its face, since CC arguably is the catalyst to the colonization of a significant percent of Americans' ancestors, it makes reasonable sense to nationally recognize the event. However, when one considers CC's glaring atrocities and the likely still real emotional impact of celebrating
him with a nationally recognized day, than the only rational response as I see it is to find the competing interests counterbalance and eliminate it as a national holiday.
If unclear, the nuance to my argument is that CC Day specifically celebrates a man. I recognize the point of what his "discovery"* did for the country and that it makes sense to recognize it, so perhaps a "Discovery Day" or some such where it's not the man that is celebrated makes more sense.
*Arguably his achievement was getting totally lost looking for spices, but that's a whole other discussion not entirely relevant for this debate. For this debate we'll assume arguendo that CC made a historic achievement.