House Majority Leader Eric Cantor's decision to endorse Mitt Romney is a certified big deal.
The Virginia Republican is no highborn member of the Washington establishment - he's the GOP House leader with the closest ties to the Tea Party movement and the huge group of representatives it elected in 2010.
This was no snow-maned party elder backing Romney on national television - it was a conservative young gun. Why Romney? Why now? Cantor said on Meet the Press that Romney's "bold pro-growth, pro-jobs plan for the future" is what sold him. According to Cantor's aides, Romney's comprehensive detailing of his economic proposals showed the majority leader how much the two men had in common. They spoke on the telephone last week, and then there was Cantor on Sunday morning, telling the world that he has cast his Virginia primary ballot for Mitt.
But then there is this: Cantor knows that the Republican House majority, which he's accountable for preserving, will be far more secure if the GOP can wrap up its divisive primary season and fall in line behind the presidential nominee.