大权在握: the great power is within one's grasp.; got one's hands on power; have [hold] in one's hands immeasurable power; hold real power in one's hand; wield the sceptre; at the helm of a state
大权旁落: one's power has been transferred into the hands of others.; a chief loses power to those under him.; allow one's power to fall into another's hands; let power pass into others' hands; lose