Speculation ranges from the wildly malevolent to the rather loopily innocent.
At one end of the spectrum is the scenario wherein these campaign officials — including perhaps Flynn, perhaps even Trump — are compromised because of tainted business or political activities known to the Russians, to whom they are now captive. A fevered conspiracy in my view, but there are non-certifiable people who consider it possible.
At the benign end of the spectrum is that the easily flattered Trump imagines himself the great dealmaker who overnight becomes a great statesman by charming Vladimir Putin into a Nixon-to-China grand bargain — we jointly call off the new Cold War, join forces to destroy the Islamic State and reach a new accommodation for Europe that relieves us of some of the burden of parasitic allies.
To me, the idea is nuts, a narcissistic fantasy grounded in neither strategy nor history. But that doesn’t mean Trump might not imagine it — after all, he maintains that if we had only stayed in Iraq to steal its oil, we wouldn’t have the Islamic State. And if this has indeed been his thinking about Russia, it would make sense to surround himself with advisers who had extensive dealings there.