The Nassau County executive, Thomas R. Suozzi, will announce his candidacy for the Democratic nomination for governor on Feb. 25, aides to his campaign and his administration said last night. He will face Attorney General Eliot Spitzer, who has a huge lead in early fund-raising, opinion polls and endorsements. As a moderate from the suburbs, Mr. Suozzi poses a counterpoint to Mr. Spitzer, who is a liberal from the city. Also yesterday, in another contested Democratic race, H. Carl McCall, the former state comptroller and 2002 Democratic nominee for governor, bypassed some better-known candidates in the race to succeed Mr....