I think that - within the system of the values and ethics portrayed in LOTR - it may be more probable that the call, i.e. the evil influence of the Ring on its bearer, is less defined by the actual power of the bearer, but more by the will to power, the delusions of grandeur the current bearer has.
To Bilbo and Gollum, the Ring did not do much harm (OK, to Gollum, yes, but he already was frankly said a freak and had it for centuries) -- that is because Bilbo did not even know about the Ring's great power, and his only wishes were to lead his quiet comfortable hobbit life and disappear every now and then from uninvited guests. The Ring had few intents of power which it could amplify in its bearer. For Gollum, it is quite the same, his thinking mainly concentrated on fish and nice dark places. Only later, when the Ring is right next to him and after he already got to know that it was a very powerful item, did he get images of a great Gollum who would make everybody pay.
Boromir, on the other hand, would have used the Ring very much, we can assume; to throw down Mordor, then all other enemies of Gondor, then maybe some other free peoples, and install a Gondorian empire over Middle-Earth (and farther? Ar-Pharazôn had similar ideas... could the Ring have had something to do with that?). Such goals as Boromir's likely were a much more fertile field for the corrupting influence of the Ring.
Certainly, Boromir was also more powerful than Frodo or Gollum; or Sam, but he already got delusions of a garden-ization of the world when he first wore it. But that may just be a coincidence, or the case that the powerful always seek more might still.
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