Reporter Dana Bash says Romney will endorse from Boston.
For you number crunchers, Romney had 291 delegates that will likely go to McCain--putting the Arizona Senator extremely close to the 1,191 delegates needed to secure the Republican nomination. Right now, according to Real Clear Politics, McCain has 825 delegates. If all of Romney's delegates to go McCain, McCain will only be 75 delegates shy of the nomination--officially ending Mike Huckabee's campaign.
Bash says: "I'm told that Governor Romney formally made this decision this morning. Talking to sources familiar with Governor Romney's thinking over the past several days, really since the lats week, it was pretty clear he was moving in this direction of formally endorsing John McCain. The question was what about those delegates, that he had wanted to hold on to going into the general election...You have to remember when he dropped out, Fredricka, at the Conservative Political Action Conference, he gave a pretty big nod to John McCain there saying that he thinks it is important for Republicans to unite in order to fight."
Update: Fox News says the endorsement will be made at 3:30 pm.