Condoleezza Rice assists Republican in key Senate race

Former Secretary of State Condoleezza Rice is coming to the defense the likely Republican candidate in one of this year's most critical Senate races.

Rice appears in a new television ad, sponsored by the super PAC American Crossroads, backing Republican Dan Sullivan for his work in Bush administration. The ad responds to an attack from a Democratic super PAC, Put Alaska First, which characterizes Sullivan as a carpetbagger, pointing out that he purchased a non-residential fishing license in 2009.

Sullivan is the favorite to win the GOP primary on Aug. 19 in the race to challenge Alaska's Democratic Sen. Mark Begich. In another apparent attempt to make Sullivan's ties to the state an issue, Begich's latest ad stresses his Alaskan roots. It notes that his father, Democratic congressman Nick Begich, died in a plane crash in Alaska.

Republicans need to pick up six seats to take control of the Senate this November, so they're eyeing the Alaska Senate race closely. Begich is considered one of the most vulnerable Democratic senators in the country.

Yet another outside group, the pro-Democrat group American Bridge, is jumping into the mix with an online ad it is running in Alaska and four other states (Arkansas, Colorado, Louisiana, and Michigan). The ad attacks the Koch-funded Americans For Prosperity for interfering in races across the country. Democrats this year are hitting the billionaire Koch brothers hard for their political spending.