FACTBOX: Key dates in the U.S. presidential campaign

(Reuters) - Below is a calendar of the remaining U.S. states' 2008 presidential nominating contests as well as other key dates in the campaign for the White House.

In some states the contests are non-binding and separate caucuses or conventions are scheduled to select delegates to the national conventions.

Arizona Sen. John McCain is the presumptive Republican nominee. Illinois Sen. Barack Obama has a nearly insurmountable lead over New York Sen. Hillary Clinton for the Democratic nomination.

MAY

* May 13: Nebraska (Republican), West Virginia

* May 16-18: Hawaii's Republican Party will conduct its state convention; delegates are selected during a week-long process.

* May 20: Kentucky, Oregon. Obama's campaign expects to clinch a majority of pledged delegates after these contests

* May 20: Candidates' April fundraising details to be released

* May 27: Idaho (Republican)