Barclays is a tough one, they seem to have figured out a way to weed out us churners. I have been turned down 3 times over the last 7 months with them. Last time I called the recon line they said to get approved I would need to stop applying for other cards for about 12 months...not going to happen.

Data point
778 credit score
current multiple personal and business accts with
Chase
Citi
Amex
US Bank
Bank of America

Barclays is the only bank I have been turned down by, I think I was black listed by them because I cancelled a couple cards quickly after I got the bonus.