Switch loses power and clients can't get back on the network after power comes back up

We have a branch site that has lost power twice this month. We use ISE for our NAC and our clients at the branch authenticate to it. When this power outage happens and the clients try to come back online, the client machines fail to authenticate or gets denied network access. For the immediate future, I will make sure everything is on a proper power backup so this doesn't happen again but until then, I just want to know what can be done to quickly get the client to properly authenticate to ISE.