The Note: Mike Huckabee's Challenge To Senators Seeking The White House

— -- NOTABLES

--RESIGN OR RUN, HUCKABEE SAYS: Former Arkansas Gov. Mike Huckabee's opponents in the race for the White House who are senators should either resign or drop out of the contest, he said on "Good Morning America" today. "If a person has a job that the taxpayers are paying for, shouldn't that person do that job?" Huckabee, a Republican who said Tuesday he was running for president, told ABC'S GEORGE STEPHANOPOULOS on "GMA." Three of his opponents in the Republican presidential field are U.S. senators: Sens. Rand Paul, Ted Cruz and Marco Rubio. Asked whether he thought his opponents should resign, he called it a clear choice. "I just believe it's a matter of integrity to say, 'I don't want this job that I just got elected to, I think I want another job,'" he said."OK, then resign the job you want, or the job you have, and go out there and seek the one you want." More from ABC's BEN GITTLESON: http://abcn.ws/1H0Hm2C

--HUCKABEE VS. CLINTON, BUSH: Huckabee announced yesterday he is running for president in his hometown of Hope, Arkansas. "It seems perfectly fitting that it would be here that I announce that I am a candidate for president of the United States of America," Huckabee told the crowd. And while he didn't mention the likely Democratic nominee, Hillary Clinton, by name, he did refer to the controversy over her family's foundation. "I don't have a global foundation or a taxpayer-funded check to live off of," he said, after asking for contributions. "I grew up blue collared, not blue blooded." http://abcn.ws/1ci6EMK

--ANALYSIS -- ABC's RICK KLEIN: The Democratic National Committee's announcement that the party will hold six presidential debates really means that Hillary Clinton will appear at six debates. She was the only candidate or potential candidate to quickly and fully endorse the announcement - with an uncharacteristically swift Tweet. More telling was Martin O'Malley's response, measured but warning that "exclusivity does no one any favors." The fact may be that getting Clinton's buy-in is all the DNC needs to cement a debate structure. But for Clinton rivals who want as much exposure as possible, a top-down approach will be hard to hold to. If O'Malley and Bernie Sanders go rogue and participate in non-sanctioned debates, would Clinton even want to be at sanctioned debates without them?

--TODAY ON THE TRAIL: Fresh off his announcement yesterday, Mike Huckabee returns to Iowa, the scene of his rise in 2008, ABC's CHRIS GOOD notes. He tours a valve manufacturer in Oskaloosa and visits with employees. Later he'll host a rally at Living History Farms in Urbandale. John Kasich is in New Hampshire for a business roundtable in Concord and at meet-and-greet in Nashua. Hillary Clinton will be in the Bay Area today for a pair of fundraisers.

THE BUZZ

with ABC's MICHELLE MANZIONE