I did a double app for One Pass Plus and United Explorer cards.
Was initially denied (via mail) for both: One pass, because "you have the maximum credit", and Explorer because "too many applications".
Called Recon: They approved me for the One pass after moving credit over from a different Chase Card that I have, but for the Explorer, they said "you cannot apply for both the Explorer and One Pass cards within a 6 month timeframe because they are very similar"
And so, I could not get approved for the explorer card.
What do you think? try again?