The Democratic U.S. senate primary is likely to be as hard fought and negative as the GOP primary. The two races have much in common.
Both contests feature a U.S. house member or former member, representing Albuquerque, against an opponent who has won a statewide election.
In the GOP primary, former Rep. Heather Wilson and Lt. Gov. John Sanchez do battle.
In the Democratic primary, Rep. Martin Heinrich and state Auditor Hector Balderas face off.
Wilson represented Albuquerque for more than 10 years, never losing an election. She left her seat and unsuccessfully ran statewide in the 2008 GOP senate primary to replace Sen. Pete Domenici.