Lee Hamilton, a former Democratic congressman who was the co-chairman of the 9/11 Commission, will endorse Barack Obama Wednesday.

In an interview with Bloomberg's Julianna Goldman, Hamilton said of Obama, "I read his national security and foreign policy speeches, and he comes across to me as pragmatic, visionary and tough. He impresses me as a person who wants to use all the tools of presidential power." Goldman also reports that Hamilton "said he agreed with Obama's position on meeting with U.S. adversaries such as the leaders of Iran without conditions."

As I always note around this time, my standard disclaimer about the relative importance -- or lack thereof -- of endorsements applies here. With the age of machine politics over, your average politician doesn't have the kind of mobile turnout operation an endorsement used to bring with it.

Still, there are reasons why Hamilton's endorsement might have at least some small effect, and why some members of the media are already claiming that this is potentially significant for Obama. First, Hamilton's home state is Indiana, which hosts a primary on May 6. Second, Hamilton is a longtime heavyweight in Democratic foreign policy circles. Time's Karen Tumulty recalls:

Back in the latter half of the Reagan era, when I was a brand-new reporter to Washington covering Capitol Hill, the Speaker of the House's press secretary -- an excitable young man named Chris Matthews -- gave me a valuable bit of advice for reporting about the arcane world of foreign policy: If you want to know where the House Democrats are going to end up, and how they are going to get there, go talk to Lee Hamilton, the number two Democrat on the House Foreign Affairs Committee. The Indiana Congressman was the closest thing the party had to a rudder in those years, and when he spoke -- always quietly, when everyone else was shouting -- people in both parties knew that they should stop and listen.

Hamilton retired from Congress in 1999; besides his position on the 9/11 Commission, he also co-chaired the Iraq Study Group and serves on the Foreign Intelligence Advisory Board and the Homeland Security Advisory Council.