Those big monster "shoe box like" ships, more akin to floating shopping malls with hotel facilities (or v.v.) that is seen in Vancouver does not all come from California, or whatever. Many are "homeported" there for the Alaska season.
They are not entering the Arctic and have no need for "Ice Class" notation in the part of Alaska they are visiting today. Few goes passed Glacial Bay National Park, with he odd call at Anchorage.
If they originate in Seattle, or points south, they mostly call at Victoria to meet their "foreign port" requirement.
What is coming is small ships (200-500 Pax) with high ice class that can take their "guests" to exotic parts of the Arctic or Antarctic, as well as to other places not accessible to the large "Shoe boxes". That will open up a market that has barely been touched, so far. There may be a dozen ships in that class now. Many second hand Research vessels from Soviet days.
Some of these smaller vessels visit as far north as Nome, or even transit through the North west Passage, but they are few and far between: http://www.visitnomealaska.com/bering-sea-cruises/
None of these cruises originate from US ports, or are on US flag vessels, as far as I can see.
The possibilities for any US flag Polar expedition vessels appears slim for the time being. Small converted vessels calling at ice free Alaskan ports, other then those presently on the itinerary of the large ships, should absolutely be possible.
Such vessels could be "homeported" in Anchorages and be calling at small settlements along the coast, including at island in the Bearing Strait. (You can ACTUALLY see Russia from there)
That may attract some more adventurous cruisers during the summer months. Problem is the short season. Where could such vessels find gainful employment in the off-season? Cruising outlaying islands of Hawaii maybe? Or could it be possible to attract people who like to see Northern Light to cruises in ice free waters during winter??