Viewers of yesterday’s historic March on Washington 50th anniversary commemoration may have been scratching their heads about one conspicuous absence: Senator Tim Scott.

The only sitting African-American senator did not speak from the dais at the Lincoln Memorial or attend the event as a spectator.

His failure to be included was criticized by former Republican National Committee chairman Michael Steele in an email to theGrio.

“Did it not occur to someone in planning the celebration of Dr. King’s speech that perhaps it would be important to invite to the podium the only African-American currently serving in the United States Senate? Surely his being a Republican had nothing to do with the egregious oversight,” wrote Steele.

According to organizers, Scott was offered an invitation — but only to be a witness to the proceedings, not be a participant.

A source has told Roll Call that a speaking slot for Scott wasn’t booked because he failed to accept the initial invitation to go to the ceremony in the first place.

“Much of the speaking program was created based on those who were able to confirm availability to attend the event, and thus were able to speak at the event,” the unidentified source said.

Scott reportedly received the same formal invitation that all members of Congress were sent on August 8th. The following day his office replied:

“Thank you for extending to Senator Tim Scott the invitation to the 50th Anniversary of the March on Washington on August 28th. Unfortunately, the Senator will be in South Carolina during this time, so he will be unable to attend the event. Please do, however, keep him in mind for future events you may be hosting.”

There were no Republicans in attendance at yesterday’s events which has drawn widespread criticism within the media and activist community.

While President George W. Bush did release an official statement expressing his admiration for Dr. Martin Luther King, former presidents Carter and Clinton actually appeared in person to deliver addresses alongside President Barack Obama.

The lack of GOP representation in what was supposed to be a non-partisan event has been seen as a blow to the party’s image.

“That [Republicans] would turn their backs on this event was telling of them, and the fact that they seem to want to get black votes, they’re not gonna get ‘em this way,” longtime civil rights activist Julian Bond said on MSNBC.

Although denied the chance to speak at the commemoration, Scott’s office did release this statement yesterday: “The senator believes today is a day to remember the extraordinary accomplishments and sacrifices of Dr. King, Congressman John Lewis and an entire generation of black leaders.”