Kind of a permanent weakness, then?
What about the idea that Hawaii and Iceland are similar types of hotspots that go very very deep as opposed to West Coast volcanos that are involved only with the continemtal plates? Would Yellowstone be very deep like Iceland and Hawaii?
Yellowstone and Hawaiian hotspots are similar as they are the shallow manifestations of deep magma plumes. Iceland is not a hotspot in the sense of Hawaii and Yellowstone but rather due to spreading along a plate boundary.
The Yellowstone hotspot is much older than the Cascade Volcanoes and seems to not be related.