WASHINGTON (CNN) -- When Senate Majority Leader Harry Reid scheduled a key vote Saturday on a non-binding resolution condemning the troop increase in Iraq, several 2008 presidential candidates scrambled to alter their schedules in order to make it back to Capitol Hill on time.

Five senators have pledged to interrupt their jaunts on the campaign trail and return to Washington for the vote. The sixth senator running for the White House, Arizona Sen. John McCain, has decided not to alter his schedule, electing to skip the Iraq vote.

On the Democratic side, Sen. Joe Biden of Delaware canceled two events in Iowa Saturday morning but will return to the Hawkeye State after the vote. Sen. Clinton of New York was forced to cancel a house party in New Hampshire and will not return to the Granite State after the vote. Sen. Chris Dodd of Connecticut is also trekking back from New Hampshire for the vote. And Sen. Barack Obama of Illinois was able to find an opening between events in South Carolina and Virginia to make it back for the vote.

On the Republican side, Sen. Sam Brownback of Kansas is returning from a trip to Iowa and Nebraska Friday and is hoping to immediately charter a flight to Florida after the vote.