For the past 70 years, all presidents, except Obama, have paid tribute to the fallen soldiers killed on D-Day. This year, instead of honoring the soldiers, he made a campaign trip on Air Force 1 to California to raise funds for the upcoming election.
Origins: This item claiming that President Barack Obama is the only U.S. President who has "failed to go to the D-Day Monument" on the anniversary of that event is a bit ambiguous, but by any reasonable interpretation it's far from accurate.
If the term "D-Day Monument" references any of the various monuments,
memorials, or cemeteries around the sites of the 6 June 1944 Allied landings on the Normandy coast of France, then appearances by U.S. presidents at any of those sites in commemoration of D-Day have been neither a long-established tradition nor a regular occurrence — such visits are a fairly recent phenomenon, and no president has made more than one.
The first president to travel to Normandy for D-Day was Ronald Reagan, who in 1984 attended commemorative ceremonies there for the 40th anniversary of the Allied landings. Bill Clinton attended D-Day memorial ceremonies in Normandy on the 50th anniversary of the landings in 1994, George W. Bush did so on the 60th anniversary of the landings in 2004, and Barack Obama did likewise on the 65th anniversary of the landings in 2009:
(George W. Bush also delivered a commemorative address in Normandy in 2002, but that event was held in conjunction with Memorial Day, not the anniversary of the D-Day landings.)
If the term "D-Day Monument" references the National D-Day Memorial in Bedford, Virginia, U.S. presidents have no established tradition of regularly visiting that site, which didn't even open until 2001. President George W. Bush was on hand for the dedication of the memorial on 6 June 2001, but the site has not seen a presidential D-Day visit since then.
If the term "D-Day Monument" refers to the National World War II Memorial, in Washington, D.C., that site didn't open until 2004 and has never hosted a presidential visit on D-Day.
In fact, any public presidential activity paying tribute to fallen U.S. and Allied soldiers on the anniversary of D-Day has been an exception rather than the rule in recent years. Available White House presidential schedules for 6 June going back to the beginning of the Bush administration in 2001 list no public events connected to D-Day in 2012,
Between 1944 and 2012 — a span of 68 years — exactly four U.S. presidents have attended D-Day memorial ceremonies a total of exactly six times. Barack Obama was one of them.