Political pundits have largely explained Rudy Giuliani's decline over the past few months as a direct result of two factors: a) his failed campaign strategy that abandoned the early primary states and b) John McCain's surge—the latter being a logical supposition considering both candidates are considered to vie for the same votes: moderate Republicans and independents.
However, a Smart Politics study of nearly 200 national polls finds that while McCain's surge has helped to dethrone Giuliani of his frontrunner status, support for Giuliani has been equally impacted by Mike Huckabee, and nearly as impacted by Mitt Romney.
A regression analysis was performed of 197 national GOP primary polls conducted between October 2006 and January 2008 with national percentage point support for Rudy Giuliani as the dependent variable. Here are the findings:
- A 1-point increase in support for McCain caused a .392 point drop in support for Giuliani, holding for support for Fred Thompson, Mitt Romney, Mike Hucakbee, and Ron Paul. Results were significant at the .001 level.
- However, a 1-point increase in support for Mike Huckabee caused a nearly identical .380 point drop in support for Giuliani, holding for support for Thompson, Romney, McCain, and Paul. Results were significant at the .001 level.
- Additionally, a 1-point increase in support for Mitt Romney caused a notable .313 point drop in support for Giuliani, holding for support for Thompson, McCain, Huckabee, and Paul. Results were significant at the .05 level.
Variable support for Thompson and Paul did not have a statistically significant impact on Giuliani's performance in the polls.
In short, Giuliani's decline cannot be solely attributed to the McCain surge, but, rather, a combination of McCain, Huckabee, and Romney all taking away support from the former New York City mayor in nearly equal amounts (each also winning primary or caucus contests along the way).
There may have been room at the top for both McCain and Giuliani, but not with Huckabee and Romney performing equally well.