Now some fresh pickings from the Political Grapevine:

Back Door Policy

Republican presidential candidate Mike Huckabee reportedly ducked in a back door to avoid striking writers as he entered Jay Leno's studio for his appearance on The Tonight Show Wednesday.

Earlier in the day Huckabee told reporters he supported the writers — "unequivocally, absolutely." and he said he believed the late-night talk shows had been given a dispensation by the writers guild to return to the air. But that is true only for the two shows produced by David Letterman's company.

Strikers outside the Leno studio held signs calling Huckabee a scab. And the guild's chief negotiator questioned how Huckabee could be trusted to serve as president if he did not even know that Leno's writers were still on strike.

Huckabee told FOX News this morning that he had been assured that no replacement writers were being used.

Hillary Clinton made a brief taped appearance on the Letterman show Wednesday night. It was over quickly — almost as quickly as she has used and discarded some of her campaign slogans. The Politico newspaper reports Senator Clinton has run through nearly a dozen phrases so far — including "Renew the promise of America," "In to win," "Working for change, working for you," "Strength and experience," then "Strength and experience to make change happen", "The change we need," "Ready for change, ready to lead," "The Hillary I know," "Turn up the heat... Turn America around," and a "New beginning."

Melt Down

New research is revealing that natural forces are playing a major role in the melting of sea ice, ice sheets and glaciers in the Arctic region. A study in the journal "Nature" details a natural and cyclical increase in the amount of energy in the atmosphere that moves from south to north around the Arctic Circle.

Many environmentalists have blamed the melting on man-made global warming. But the research by a Stockholm University meteorologist says the energy shift is more responsible for the melting than climate change. A second study due out soon reaches a similar conclusion.

Some researchers are disputing the results — saying the studies underestimate the role of global warming in the Arctic melting.

Strange Bedfellows

And the chairman of the USO is under fire for a deal with the liberal group MoveOn.org to provide phone cards to U.S. troops overseas. MoveOn members contributed more than $350,000 dollars to the USO.

MoveOn is the same organization that sponsored the now-famous "General Betrayus" ad in The New York Times last September.

One USO board member is calling for the firing of President Edward Powell over the deal. But the chairman of the USO board of governors says the group welcomes contributions regardless of political preferences, and took steps to make sure there were no partisan or controversial statements made when MoveOn solicited its members for donations.

FOX News Channel's Martin Hill contributed to this report.

With more than 35 years of journalism experience to draw from, Brit Hume currently serves as a senior political analyst for FOX News Channel (FNC) and contributes to all major political coverage. Hume also is regular panelist on FOX's weekly public affairs program, "FOX News Sunday" on Sundays at 2 p.m. and 6 p.m. ET. Click here for more information on Brit Hume