be in somebody's power
be within somebody's power

But since that wasn't within his power, he did the next best thing.

Together with the Council, we have done everything within our power.

But I cannot think of anything that is within your power to offer.

I knew she would have helped me had it been within her power here.

But know that you have it within your power to try.

This opportunity, as I think, it is now coming within your power to give her.

And I will do everything within my power to make sure that he never runs for office again.

But I realize that may not be within your power.

But still both objects are within your power of decision.

Then he did the only thing that still lay within his power.