WASHINGTON (AP) — Rick Santorum says he believes he would get the Republican presidential nomination if that race lasts until the GOP nominating convention.Without naming chief rival Mitt Romney, Santorum says that if the race remains undecided by the party's August gathering in Tampa, the GOP will not nominate a moderate former Massachusetts governor who has decisively outspent his opponents but been unable to knock them out of the race.Romney has a delegate lead over his remaining rivals, and his aides have said none of his competitors are on a path to garner the 1,144 delegates needed to clinch the nomination.But Santorum said Monday that the primary contests are now moving to states in which Romney will be less successful in winning delegates.Santorum was interviewed on NBC's "Today" show.