According to Politico:
Reid says the bill deserves a hearing and reflects his commitment to supporting gun rights in a state that sanctifies the Second Amendment. Other Democrats say he approved the vote out of personal political necessity — to avoid the ire of the National Rifle Association during the 2010 elections.
“Nobody’s angry at Harry, but it’s created a problem for us,” says a Democratic aide, speaking on condition of anonymity. “There’s a huge level of sympathy for him, because we don’t want to have another Daschle situation.”
That was, of course, a reference to Tom Daschle, the last Democratic majority leader who was knocked off in 2004, by Republican John Thune.
By astounding coincidence (not), Thune, now the No. 4 man in the Senate, just happens to be the guy who authored the current amendment to allow licensed gun owners to transport their weapons across state lines.
“This has nothing to do with electoral politics,” said Reid spokesman Jim Manley, who emphasized that the amendment has the support of many other Democrats besides Reid.
h/t Say Uncle.