England is very much in vogue in America. Everything English is admired. If somebody has a British accent people here are impressed. A Brit here could get hired just because of the way he talks.
But I can't emphasize enough that the US never "joins" with other countries. It never "merges". Some people here sort of think Canada is a different country. They flee to it if they don't like US policy. But others probably think it's a US territory or something. But they wouldn't merge with it. They'd probably admit Alberta or British Columbia as a new state. But you see it's contiguous, and it's already part of North America.
To "merge" with Britain would be inconceivable in the present age. People here think of Europe as faraway. They think of England as the Mother Country. They'd be more pleased if Britain did some of the work the way it used to. For instance, if it wanted to move troops into Iraq and escalate things, nobody would object. If it took a lead in certain areas of foreign policy, it's the only country that could get away with it. In other words, I think the Churchillian idea of the British Empire working with America could still prevail here which is why I suggested it. It wouldn't have to be the Empire of old. It could be something different.