21.   But he could never have built such a potent force without great amounts of help from other countries.

22.   But men, especially white men, remain a potent political force, perhaps even more complicated to court.

23.   But the market might also be seen as a malleable whole with potent forces exerting varying degrees of pressure at any given moment.

24.   But there is another potent force at work in these deals between industry giants.

25.   By dipping into his vast fortune, Forbes can guarantee that he will be a potent force in the Republican campaign until the very end.

26.   Clinton began the remarkable transition Wednesday from a quarter century of derivative power as a political spouse to a potent force in her own right.

27.   Denial is a very potent force.

28.   Dellums came to Washington during an era when the Left promised to be a potent force in American politics.

29.   For presidential candidates, veterans can be a potent political force.

30.   Gradually, the Broad Channel Civic Association turned itself into a potent lobbying force.