Former Senator Phil Gramm was a co-chairman of the McCain campaign, and McCain's chief economic adviser. He stepped down from the campaign on July 18, 2008, about a week after he made remarks to "The Washington Times" about the nation's economic conditions. Gramm had said, "You've heard of mental depression; this is a mental recession," and "We have sort of become a nation of whiners. You just hear this constant whining." McCain had quickly repudiated Gramm's remarks, saying "Phil Gramm doesn't speak for me, I speak for me. I strongly disagree." When asked if Gramm was still in contention for the U.S. Treasury Secretary position as previously speculated, McCain had said, "I think Senator Gramm would be in serious consideration for ambassador of Belarus, though I'm not sure the citizens of Minsk would welcome that." Gramm said upon leaving that he had become a distraction to the campaign. A McCain campaign ad crafted by Fred Davis compared Barack Obama to known celebrities such as Britney Spears and Paris Hilton, and questioned his readiness to lead while criticizing his energy policy. The ads resulted in a tightening of Obama's lead in polls. After the election, Obama deputy campaign manager Steve Hildebrand said: "It was the first time during the general election where I started to freak out... I thought if they can brand him as a celebrity rather than as a serious leader we're going to be in serious trouble." McCain began a search for a running mate to join the Republican ticket after clinching the Republican nomination. Former candidates Mitt Romney and Mike Huckabee were mentioned as possibilities, as were many other leaders in the Republican Party and the business world. Over Memorial Day weekend, McCain invited Romney, Florida Governor Charlie Crist, and Louisiana Governor Bobby Jindal to his Sedona, Arizona ranch for informal get-togethers intended to assess personal chemistry for possible running mate selection. McCain then announced plans to reveal his running mate the day following the conclusion of the Democratic National Convention, and just a few days before the start of the Republican National Convention. During the running mate deliberations, McCain had favored Joe Lieberman, who shared his romantic sense of righteousness and honor. But the opposition from social conservatives, who objected to Lieberman's pro-choice views, was too strong, and a Lieberman pick might have caused a floor fight at the convention. McCain wanted someone who would shake up the race and reinforce his image as a maverick, so he decided against more conventional choices on his short list including Romney and Governor Tim Pawlenty.