Santos first appears in Season 6 as a member of the United States House of Representatives, who is regarded as an effective legislator and a potential candidate for Governor of Texas. Despite his age and policy savvy, Santos is about to retire due to his frustration with Washington politics. However, then Deputy White House Chief of Staff Josh Lyman persuades him to run for president of the United States and becomes his campaign manager. Santos begins his run for the Democratic nomination as a long-shot candidate with little name recognition or funding; polls show him far behind the sitting Vice President Bob Russell and the former Vice President John Hoynes. However, as the primaries progress, Santos rises to third place in most opinion polls. On the day before the California primary, Hoynes is engulfed in a sex scandal, resulting in an upset victory after an implicit endorsement of Santos from the governor of California.