(AP Photo/Eric Risberg)

The departure of senior staff has had no effect on the public's opinion of John McCain's presidential candidacy, according to the new Gallup poll. The poll, a national telephone survey of 1,001 adults between July 12 and July 15, shows McCain (16 percent support) running in third place for the 2008 GOP presidential nomination, behind former New York City mayor Rudolph Giuliani (30 percent) and former Tennessee senator Fred Thompson (20 percent). McCain was also at 16 percent support in the previous Gallup survey conducted between July 6 and July 8. On July 10 McCain's campaign manager Terry Nelson and senior political strategist John Weaver resigned from the campaign. Yesterday, July 16, McCain's national communications staff also quit. The Gallup poll findings are a reminder that stories the national press corp deem monumental--such as McCain's campaign shakeup--do not always have immediate political consequences. This is not to say that all is well with the McCain campaign, however. According to Gallup, McCain began the year with the support of 27 percent of respondents nationwide. His decline has been steady, in inverse proportion with Thompson's ascendance into second place. The Gallup poll also found that McCain's favorability rating among self-described conservatives and moderates has declined substantially since the first quarter of 2007. Gallup averaged several national polls from February and March, compared those results with an average of polls taken in June and July, and found a 10 percent decline in the percentage of conservatives who view McCain favorably, from 61 to 51 percent. The decline in the percentage of moderates who view McCain favorably was 18 percent, from 61 to 43 percent. These findings suggest a pincer effect is hurting McCain. On one side, his support for President Bush's immigration initiative has hurt his image among conservatives. On the other side, his vocal advocacy of the surge strategy in Iraq is probably eroding his support from moderates. When you combine the pincer effect with McCain's well-publicized fundraising troubles, you can see the substantial difficulties he faces in winning the GOP nomination. Who would benefit the most from McCain's withdrawal from the presidential race, according to Gallup? Giuliani. He'd gain 8 points if McCain withdrew, increasing his lead from 30 to 38 percent.