The phrase "usurp power" is correct and usable in written English.
It generally means to take power or authority without having the legal right to do so. For example, "The dictator attempted to usurp power from the elected government."
Sensing a potentially powerful issue, Republicans have repeatedly accused Mr. Obama of preparing to usurp power from Congress and of wildly overstepping the authority of his office.
The potential for such groups to usurp power, or undermine social and economic stability is likely to increase.
"I did not usurp power," he later wrote, "but I did greatly broaden the use of executive power".
He said that the ultimate goal of the demonstrators was to "destroy Russian statehood and usurp power".
But that list ended with a swipe at Cooper, who Berger's office accused of planning to usurp power.
After Ukrainian society rose up against this attempt to usurp power, Yanukovych reportedly favored using the Army against the peaceful protestors who flooded central Kiev.
The case against us included a letter from the central elections committee's chairman, Vladimir Churov, accusing Golos of "attempting to usurp powers of authority".
It is hidden in Viper Manor the home of a terrible and powerful aristocrat named Lynx, who gained control of the estate after usurping power from and killing the Acacia Dragoons, a familial unit of warriors.
In some countries, military officers usurped power, jettisoned democracy, and proclaimed themselves overlords.
Initially Marcos did some worthwhile things but then he usurped power.
They would call him a squatter in Downing Street, insisting he had usurped power.
