There are no blue states. There are only blue cities. If they wish to "secede", what that indicates is that they have not thought through how easy it is to block a road.
This is also what I point out to my fellow Canadians who insist that Canada has political-economic "friends" in "blue states"; if you look at a map from the 2024 election even the "bluest" of states had walls of red and sometimes especially right next to the Canadian border. Western New York and Vermont both have counties right across the border that swung for Trump sometimes by margins as much at 15%.
There's no easy way out of this quagmire. A deep horrible somewhat tribal division has spread in North American society around a pile of issues and it's become pivoted around a supposed "left"-right axis but it's really about a whole pile of other issues and unresolveable grievances. Prosperity is declining in western countries, and distribution of wealth is becoming drastically unequal. And neither liberal or conservative ideological centres (the only two allowed in American politics) have any kind of solution.
The same infection is here in Canada as well, but less intense. As usual we're just 10 years behind whatever trend happens there.