The memorial service for Nelson Mandela is a big deal. "We're now on 91 Heads of State & Gov confirmed plus 10 former Heads of State, 86 Heads of delegations & 75 Eminent Persons," tweeted South African government spokesman Clayson Monyela on Monday. Among those leaders attending are the UN Secretary General, Ban Ki-Moon, British Prime Minister David Cameron, and French President Francois Hollande -- plus, of course, President Obama and former Presidents Carter, Clinton, and George W. Bush. Dozens of lesser leaders, plus celebrities like Bono and Oprah Winfrey, will also be there.

From the United States Congress, House Speaker John Boehner appointed a 23-member delegation, led by Illinois Republican Rep. Aaron Schock and dominated by members of the Congressional Black Caucus, all Democrats. Their plane departed early Monday morning.

But what about the U.S. Senate? Senators could have joined the representatives on the congressional plane. But exactly one -- one -- senator will be at the Mandela memorial: Texas Republican Ted Cruz. No member of the majority Democratic or minority Republican leadership will attend. And not the Senate's only black Democrat, Cory Booker, or the Senate's only black Republican, Tim Scott.

Why such a poor turnout from the world's greatest deliberative body? "Remember, the presidential delegation didn't invite any members of Congress," says a Senate Republican aide. "The delegation the House put together only took shape over the weekend, so it was a scramble to even make it available to members in the first place (and to those who could get back to DC in time to make the flight). So I wouldn't read anything into that small attendance."

A winter storm across much of the country also had something to do with it. "The [congressional delegation] plane left before dawn, and a lot of members who wanted to go had their flights or trains canceled or delayed," says a Senate Democratic aide.

So how did Cruz make it? There's no doubt the freshman from Texas has shown a lot of energy in his 11 months in the Senate, and he did it again this time: He made the plane when others didn't. Says a spokesman: "Sen. Cruz believes that once-in-a-generation historical leaders, whatever their strengths/weaknesses, who accomplish extraordinary things, should be recognized and celebrated. And he personally wants to be part of demonstrating the recognition in American of the transforming power of the end of apartheid."

Cruz took some hits in the hours after Mandela's death when he posted a Facebook item saying Mandela "will live in history as an inspiration for defenders of liberty around the globe." Some of his followers criticized Cruz for praising Mandela, and some in the press picked up the story as an example of alleged Republican intolerance. But in the end, Cruz was unfazed -- and he made the plane.