New Mexico Republicans chose from among four candidates Tuesday to try to unseat first-term Democratic Sen. Jeff Bingaman. State Sens. Bill Valentine and Joe Carraro, party activist Corky Morris and former U.S. Interior Department official Rick Montoya each argued that he was the right candidate to mount a successful challenge to the man Republicans believe is too liberal for New Mexico. In the presidential primary, Massachusetts Gov. Michael Dukakis was favored over Jesse Jackson in the race for 24 Democratic delegates. Vice President George Bush was unopposed for 26 Republican delegates. In the state's 1st Congressional District, Republican Rep. Manuel Lujan Jr. was retiring after 20 years. Three Republicans sought the nomination, including Lujan's younger brother Edward, the former state GOP chairman. Eight Democrats sought their party's nomination, including former state Land Commissioner Jim Baca.