The last Republican nominee is set to weigh in on the next one as John McCain will reportedly back Mitt Romney during an appearance in New Hampshire today. (The news was the first big scoop by the new political team at BuzzFeed.) McCain defeated Romney in a bitter primary fight in 2008, but the two have since mended fences with Romney campaigning on his behalf both for president and in a tough re-election fight for McCain's Senate seat in 2010. 

While the old "maverick" is hardly a beloved figure among the Republican establishment — he even had to fend off an intraparty primary challenge in 2010 — McCain's endorsement will be a big win for Romney among moderates and independents, solidifying his main argument that he's the man to beat President Obama. McCain couldn't do it himself, of course, but he's still a popular figure on the national stage and a dean of Washington who stands in stark contrast to the Tea Party strain running through the G.O.P. With the exception of anyone named Bush, he's probably the most prominent Republican endorsement available. Combine that with landslide win in New Hampshire and the Romney train will pick up some serious steam.