The road ahead

Through Nov. 20: Filing period for New Hamsphire primary

Nov. 10: Republican debate in Milwaukee

Nov. 14: Democratic debate in Des Moines

Dec. 15: Republican debate in Las Vegas

Dec. 19: Democratic debate in Manchester, N.H.

Jan. 17: Democratic debate in Charleston, S.C.

Feb. 1: Iowa caucuses (both parties)

Feb. 6: Republican debate in New Hamsphire

Feb. 9: New Hampshire primary (both parties)

Feb. 10: Republican debate in Florida

Feb. 13: Republican debate in South Carolina

Feb. 20: Nevada Democratic caucuses and South Carolina Republican primary

Feb. 23: Nevada Republican caucuses

Feb. 26: Republican debate in Houston

Feb. 27: South Carolina Democratic primary

March 1: Super Tuesday. Primaries/caucuses in several states, including Minnesota

–21: Republican National Convention in Cleveland

–28: Democratic National Convention in Philadelphia

Nov. 8: 2016 Election Day

Jan. 20: Inauguration of the new president

Why does it matter?

Iowa caucuses: The first test of candidates' staying power. Some will drop out after the votes are tallied.

N.H. primary: Candidates who win — or exceed expectations — here and in Iowa, will have momentum.

Super Tuesday: Multiple-state voting could provide a big boost to some candidates — and doom others.

RNC: A chance for the party's ticket to set general election themes and start making the case against the Democrats.

DNC: How strongly the nominee embraces President Obama's legacy will be a clue to fall's core messages.