What size pflueger president should I put on a st croix medium fast action 6'6 rod

I would go with the 2500. All my spinning reels are 2500s, perfect size IMO.

I like the 30 size

6930 or 6935. I have a 35 which I use with 15# braid and am very pleased with it.

Go 30. 35 is on the large size for Bass fishing. I have a 35 and my wife has a 30, wish I got the 30 size.

6930 or 6935. I have a 35 which I use with 15# braid and am very pleased with it.

I agree either if these sizes will work, I have both but prefer the 30 size

30

30 definitely, 35 is to big for bass fishing.

I wouldn't say 35 is too big, it's a pretty reasonably sized reel and the wider spool would probably be more beneficial for mono/flouro. The pflueger 30 size is the goldilocks reel for me though, got one spool with 6lb mono for trout and the other with 20lb braid for bass.

30 for sure. I wouldn't go 35 unless the rod was 7'+.