indicates candidate won party nomination

Feb. 1 Iowa caucuses   Winner in 2012   2008
  Democratic 52 delegates n/a Barack Obama
  Republican 30 delegates Rick Santorum Mike Huckabee
Feb. 9 New Hampshire primary   Winner in 2012   2008
  Democratic 32 delegates n/a Hillary Clinton
  Republican 23 delegates Mitt Romney John McCain
Feb. 20 Nevada caucuses   Winner in 2012   2008
  Democratic 43 delegates n/a Hillary Clinton
  South Carolina primary   Winner in 2012   2008
  Republican 50 delegates Newt Gingrich John McCain
Feb. 23 Nevada caucuses   Winner in 2012   2008
  Republican 30 delegates Mitt Romney Mitt Romney
Feb. 27 South Carolina primary   Winner in 2012   2008
  Democratic 59 delegates n/a Barack Obama
March 1 Alabama primary   Winner in 2012   2008
  Democratic 60 delegates n/a Barack Obama
  Republican 50 delegates Rick Santorum Mike Huckabee
  Alaska caucuses   Winner in 2012   2008
  Republican 28 delegates Mitt Romney Mitt Romney
  Arkansas primary   Winner in 2012   2008
  Democratic 37 delegates n/a Hillary Clinton
  Republican 40 delegates Mitt Romney Mike Huckabee
  Colorado caucuses   Winner in 2012   2008
  Democratic 79 delegates n/a Barack Obama
  Georgia primary   Winner in 2012   2008
  Democratic 116 delegates n/a Barack Obama
  Republican 76 delegates Newt Gingrich Mike Huckabee
  Massachusetts primary   Winner in 2012   2008
  Democratic 116 delegates n/a Hillary Clinton
  Republican 42 delegates Mitt Romney Mitt Romney
  Minnesota caucuses   Winner in 2012   2008
  Democratic 93 delegates n/a Barack Obama
  Republican 38 delegates Rick Santorum Mitt Romney
  Oklahoma primary   Winner in 2012   2008
  Democratic 42 delegates n/a Hillary Clinton
  Republican 43 delegates Rick Santorum John McCain
  Tennessee primary   Winner in 2012   2008
  Democratic 76 delegates n/a Hillary Clinton
  Republican 58 delegates Rick Santorum Mike Huckabee
  Texas primary   Winner in 2012   2008
  Democratic 252 delegates n/a Hillary Clinton
  Republican 155 delegates Mitt Romney John McCain
  Vermont primary   Winner in 2012   2008
  Democratic 26 delegates n/a Barack Obama
  Republican 16 delegates Mitt Romney John McCain
  Virginia primary   Winner in 2012   2008
  Democratic 110 delegates n/a Barack Obama
  Republican 49 delegates Mitt Romney John McCain
March 5 Kansas caucuses   Winner in 2012   2008
  Democratic 37 delegates n/a Barack Obama
  Republican 40 delegates Rick Santorum Mike Huckabee
  Kentucky caucuses   Winner in 2012   2008
  Republican 46 delegates Mitt Romney John McCain
  Louisiana primary   Winner in 2012   2008
  Democratic 59 delegates n/a Mike Huckabee
  Republican 46 delegates Rick Santorum Barack Obama
  Maine caucuses   Winner in 2012   2008
  Republican 23 delegates Mitt Romney Mitt Romney
  Nebraska caucuses   Winner in 2012   2008
  Democratic 30 delegates n/a Barack Obama
March 6 Maine caucuses   Winner in 2012   2008
  Democratic 30 delegates n/a Barack Obama
  Puerto Rico primary   Winner in 2012   2008
  Republican 23 delegates John McCain
March 8 Hawaii caucuses   Winner in 2012   2008
  Republican 19 delegates Mitt Romney
  Idaho primary   Winner in 2012   2008
  Republican 32 delegates Mitt Romney John McCain
  Michigan primary   Winner in 2012   2008
  Democratic 147 delegates n/a Hillary Clinton
  Republican 59 delegates Mitt Romney Mitt Romney
  Mississippi primary   Winner in 2012   2008
  Democratic 41 delegates n/a Barack Obama
  Republican 40 delegates Rick Santorum John McCain
March 12 District of Columbia convention   Winner in 2012   2008
  Republican 19 delegates Mitt Romney John McCain
  Wyoming convention   Winner in 2012   2008
  Republican 29 delegates Mitt Romney Mitt Romney
March 15 Florida primary   Winner in 2012   2008
  Democratic 246 delegates n/a Hillary Clinton
  Republican 99 delegates Mitt Romney John McCain
  Illinois primary   Winner in 2012   2008
  Democratic 182 delegates n/a Barack Obama
  Republican 69 delegates Mitt Romney John McCain
  Missouri primary   Winner in 2012   2008
  Democratic 84 delegates n/a Barack Obama
  Republican 52 delegates Rick Santorum John McCain
  North Carolina primary   Winner in 2012   2008
  Democratic 121 delegates n/a Barack Obama
  Republican 72 delegates Mitt Romney John McCain
  Ohio primary   Winner in 2012   2008
  Democratic 159 delegates n/a Hillary Clinton
  Republican 66 delegates Mitt Romney John McCain
March 22 Arizona primary   Winner in 2012   2008
  Democratic 85 delegates n/a Hillary Clinton
  Republican 58 delegates Mitt Romney John McCain
  Idaho caucuses   Winner in 2012   2008
  Democratic 27 delegates n/a Barack Obama
  Utah caucuses   Winner in 2012   2008
  Democratic 37 delegates n/a Barack Obama
  Republican 40 delegates Mitt Romney Mitt Romney
March 26 Alaska caucuses   Winner in 2012   2008
  Democratic 20 delegates n/a Barack Obama
  Hawaii caucuses   Winner in 2012   2008
  Democratic 34 delegates n/a Barack Obama
  Washington caucuses   Winner in 2012   2008
  Democratic 118 delegates n/a Barack Obama
April 5 Wisconsin primary   Winner in 2012   2008
  Democratic 96 delegates n/a Barack Obama
  Republican 42 delegates Mitt Romney John McCain
April 9 Wyoming caucuses   Winner in 2012   2008
  Democratic 18 delegates n/a Barack Obama
April 19 New York primary   Winner in 2012   2008
  Democratic 291 delegates n/a Hillary Clinton
  Republican 95 delegates Mitt Romney John McCain
April 26 Connecticut primary   Winner in 2012   2008
  Democratic 70 delegates n/a Barack Obama
  Republican 28 delegates Mitt Romney John McCain
  Delaware primary   Winner in 2012   2008
  Democratic 31 delegates n/a Barack Obama
  Republican 16 delegates Mitt Romney John McCain
  Maryland primary   Winner in 2012   2008
  Democratic 118 delegates n/a Barack Obama
  Republican 38 delegates Mitt Romney John McCain
  Pennsylvania primary   Winner in 2012   2008
  Democratic 210 delegates n/a Hillary Clinton
  Republican 71 delegates Mitt Romney John McCain
  Rhode Island primary   Winner in 2012   2008
  Democratic 33 delegates n/a Hillary Clinton
  Republican 19 delegates Mitt Romney John McCain
May 3 Indiana primary   Winner in 2012   2008
  Democratic 92 delegates n/a Hillary Clinton
  Republican 57 delegates Mitt Romney John McCain
May 10 Nebraska primary   Winner in 2012   2008
  Republican 36 delegates Mitt Romney
  West Virginia primary   Winner in 2012   2008
  Democratic 37 delegates n/a Hillary Clinton
  Republican 34 delegates Mitt Romney
May 17 Kentucky primary   Winner in 2012   2008
  Democratic 60 delegates n/a Hillary Clinton
  Oregon primary   Winner in 2012   2008
  Democratic 74 delegates n/a Barack Obama
  Republican 28 delegates Mitt Romney John McCain
May 24 Washington primary   Winner in 2012   2008
  Republican 44 delegates Mitt Romney John McCain
June 5 Puerto Rico caucuses   Winner in 2012   2008
  Democratic 67 delegates n/a Hillary Clinton
June 7 California primary   Winner in 2012   2008
  Democratic 546 delegates n/a Hillary Clinton
  Republican 172 delegates Mitt Romney John McCain
  Montana primary   Winner in 2012   2008
  Democratic 27 delegates n/a Barack Obama
  Republican 27 delegates Mitt Romney Mitt Romney
  New Jersey primary   Winner in 2012   2008
  Democratic 142 delegates n/a Hillary Clinton
  Republican 51 delegates Mitt Romney John McCain
  New Mexico primary   Winner in 2012   2008
  Democratic 43 delegates n/a Hillary Clinton
  Republican 24 delegates Mitt Romney John McCain
  North Dakota caucuses   Winner in 2012   2008
  Democratic 23 delegates n/a Barack Obama
  South Dakota primary   Winner in 2012   2008
  Democratic 25 delegates n/a Hillary Clinton
  Republican 29 delegates Mitt Romney John McCain
June 14 District of Columbia primary   Winner in 2012   2008
  Democratic 45 delegates n/a Barack Obama
Unclear Colorado   Winner in 2012   2008
  Republican 37 delegates Rick Santorum Mitt Romney
  North Dakota   Winner in 2012   2008
  Republican 28 delegates Rick Santorum Mitt Romney