The "8" year curse. Presidents elected in an election year ending in 8 lose re election:
34. Thomas Dewey / Earl Warren (Republican): 1949-1953
35. Estes Kefauver / Adlai Stevenson (Democratic): 1953-1961
36. Nelson Rockefeller / Thurston Morton (Republican): 1961-1969
37. Hubert Humphrey / Terry Sanford (Democratic): 1969-1973
38. George Romney / Bob Dole (Republican): 1973-1981
39. Hugh Carey / John Glenn (Democratic): 1981-1989
40. John Glenn / Bill Clinton (Democratic): 1989-1993
41. Pete Wilson / James Thompson (Republican): 1993-2001
42. Dick Gephardt / Joe Biden (Democratic): 2001-2009
43. Mitt Romney / Lisa Murkowski (Republican): 2009-2013
44. Brian Schweitzer / Hillary Rodham Clinton (Democratic): 2013-2021
45. Paul Ryan / Nikki Haley (Republican): 2021-2025
46. Tom Steyer / Pete Buttigeig (Democratic): 2025-2029
47. Nikki Haley / Dan Crenshaw (Republican): 2029-2033
48. Jon Ossof / Tammy Baldwin (Democratic): 2033-Incumbent
Had Obama lost in 2012, they’d be talk about the 8 year curse. Harry Truman, Richard Nixon and George Bush all lost re-election or resigned (Nixon) after being elected in a year ending with 8
It even goes further back because Hoover (1928), Taft (1908) and Harrison (1888) all lost their reelection bid, and Hoover and Taft did so by a landslide margin.
Before Obama Grant was the last president to serve two full terms while being elected in a year ending with 8.