A day in the lives of presidential candidates Bob Russell, Matt Santos, and Arnold Vinick, who are in Iowa trying to gain support for their campaigns. Iowa is the first state in the nation to hold their presidential caucuses, and issues affecting farmers and rural areas are the focus. The most important issue on the table is the large federal subsidies for ethanol fuel given to corn growers, which is supported by Iowa residents but seen as naked pandering by the rest of the country. Josh continues to clash with Santos over winning votes instead of proposing radical policy. Donna and Josh continue to avoid speaking about the state of their relationship.

Senator Arnold Vinick easily wins the Republican nomination on the night of the New Jersey primary, but has difficulty picking a running mate. Choosing Reverend Don Butler would virtually guarantee him the presidency, but their differing views on abortion and religion would make it a political union rather than one based on shared ideology. The Democratic nomination is a toss-up between Santos and Russell; Hoynes is running a distant third. With no clear nominee going into the convention, the Democratic party risks appearing unsure about both Santos and Russell - a position that President Bartlet does not want the Republicans to be able to exploit.

Leo's preparation for the Vice Presidential debate is going badly; Santos makes his last trip home before the election; Will and Kate continue to flirt.

A nuclear accident in California sends the White House and both campaigns into overdrive. Meanwhile, China and Russia appear headed for a showdown over elections and oil in Kazakhstan.

The Vinick campaign struggles with the impact of the nuclear accident in California; Josh and Donna have a "moment".

Both candidates face vital choices about which states to campaign in; Vinick tries to put the nuclear issue behind him; Bruno finds Santos's briefcase.

Election day finally arrives; C.J. ponders job offers; the election looks too close to call.

Polls are closing across the country, and the race is too close to call; friends and colleagues react to the news about Leo.

While Santos is wrapped up in choosing his new Vice President, Helen is overwhelmed by the issues facing the new First Family. Meanwhile, Vinick must find a new road now that the election is over.