In the larger context of end-time events, "the holy people" refers to God's chosen nation, Israel. The church, however, can also be alluded to here in antitype: Peter calls the church "a holy nation, His own special people" (I Peter 2:9). Both of these groups, Israel and the church, seem to be in the process of having their power "completely shattered."
This expression in the Hebrew has the primary meaning of "broken in pieces," "scattered," or "dispersed by force." It can mean something akin to "explode." When an object explodes, its pieces fly apart, and it can no longer do what it was made to do. The individual pieces are powerless to accomplish what the whole object did. The whole is greater than the sum of its parts.
This must be part of the meaning of the verse because the word power is really the Hebrew word for "hand." The hand symbolizes a person's ability to do work, to accomplish, to act. The translators have taken it to mean the more abstract "might" or "power," but they could have rendered it as "ability," "strength," or "effectiveness."
If this is so, we can expect the church's ability to do an effective work to decline still further because our power is not yet completely shattered. That is why it is so important that we make use of the abilities still left to us: to prepare ourselves for God's Kingdom. As an encouraging Jewish proverb reminds us, "When God shuts a door, He opens a window." We can take other avenues in the meantime while the road ahead is blocked for doing a public work.