Just saw Christie on Greta. He said he called Trump yesterday to tell him he would endorse and asked Trump when he wanted to announce it. Trump said asap, can you fly down to Texas? So he did last night and announced this morning. I presume Trump knew this was going to happen during the debate last night. He knew the whole time the announcement would overshadow anything in the debate.
This more than answers the question I posed in reply #70.
It may explain why Trump wasn’t as thrown by the debate attacks last night. He had the Christie card up his sleeve, waiting to unleash it when the time was right.