Originally Posted by
tommyleo
The A321 certainly does have a mid-cabin door that is large enough for passenger boarding: door 2L. However, 2L is not used for boarding because it is near the engine and positioning a jetway at 2L risks engine damage.
There was a time, before reconfiguration to downsize F, where the 321 and the 757 boarded through 2L. It was great… you didn't have the unwashed masses dragging everything they owned through F on the way back to steerage.