Rick Santorum drops out of the race for the GOP presidential nomination. Rich Lowry calls his effort "valiant."

He started this campaign basically with his convictions and a shoestring. He got amazingly far, all things considered. He came within a few points of dealing Romney a grievous blow in Michigan and upending the race. But he never had the money and organization to compete with Romney–and those things matter. Despite his working-class pitch, he was never able to extend his reach enough beyond his evangelical base. At times his message was compelling and fresh, but by the end it seemed to boil down to a critique of Romneycare (and increasingly over-the-top attacks on Romney). The downside to his passion and sincerity was a lack of discipline and a weakness for bluster. For all those reasons, he couldn’t catch Romney. But Santorum is a man of principle who lives his convictions and is never afraid to defend them.

Sounds about right.