Announce a vice presidential running mate now.
There is a very good chance that Trump will not have 1,237 delegates by the time the Republican Convention in Clevelan opens. There is no chance that Cruz will. The Trump and NeverTrump camps are set hard and fast. The candidates alone are not likely to be able to jackhammer the delegates from that concrete. Naming a running mate now is that jackhammer.
There is a very good chance that Trump will not have 1,237 delegates by the time the Republican Convention in Clevelan opens. There is no chance that Cruz will. The Trump and NeverTrump camps are set hard and fast. The candidates alone are not likely to be able to jackhammer the delegates from that concrete. Naming a running mate now is that jackhammer.