The United States' Republicans are lining up their contenders to take on Barack Obama in the next US elections and one of their representatives could end up being the most powerful person in the world.

This weekend Republican presidential hopefuls will participate in the Iowa Straw poll - an unofficial survey of the state’s Republicans who will cast a ballot in November 2012 for the candidate they think can unseat President Obama.

Al Jazeera's Kimberly Halkett reports from the televised debate underway in Iowa.

Source: Al Jazeera