Complex sentence: He and Mel Martinez (R-Florida) were the first Hispanic U.S. Senators since 1977; they were joined by Bob Menendez (D-New Jersey) in January 2006.
Split into simpler sentences: He and Mel Martinez (R-Florida) were the first Hispanic U.S. Senators since 1977. They were joined by Bob Menendez (D-New Jersey) in January 2006.