U.S. Republican presidential hopeful Newt Gingrich says former Massachusetts Governor Mitt Romney is the weakest Republican presidential candidate since 1920.

In an interview with Fox News, Gingrich said that although Romney is leading the pack, Romney is not that strong and most conservatives oppose him.

Gingrich rejected former Pennsylvania Senator Rick Santorum’s call for him to drop out of the presidential race, saying Santorum has failed to earn trust from the conservatives.

He added that he would be able to pull down oil prices to below two dollars and 50 cents per gallon within two years after he takes office as president.