opportunistic
adj.adj. taking advantage of a situation to get what you want, often without thinking about what is right or fair.
adj. exploiting circumstances to gain an immediate advantage, often regardless of principles or consequences. Frequently describes behavior that is pragmatic rather than planned.
He made an opportunistic grab for the last seat on the bus.
The politician's opportunistic shift in policy was clearly designed to win over voters just weeks before the election.
In the absence of a strong central government, various opportunistic factions began seizing control of local resources to consolidate their own power bases.
From opportunist + -ic.
Commonly used in both political and biological contexts; in biology, it describes organisms that thrive when conditions suddenly become favorable.