Max Baucus, thirty-five year veteran of the Senate and chairman of the Finance Committee, will retire from politics rather than seek reelection from Montana voters next year. Montana is a conservative state, but Democrats have good odds for holding the seat — former governor Brian Schweitzer, who left office with strong approval ratings, has hinted at a potential run and would be well-positioned to win.

Electoral politics aside, Baucus’s retirement is almost sure to anger liberals, given his opposition to the Manchin-Toomey plan for expanded background checks. It’s one thing to oppose sensible legislation for political gain — it’s not praiseworthy, but there’s a calculus that makes sense. Opposition for its own sake, on the other hand, is frustrating, especially when it comes to something that would prevent criminals from purchasing guns.

With that said, it’s worth considering another possibility before assuming spinelessness on Baucus’s part — it could just be that the long-time Montana senator sincerely believed his constituents opposed expanded background checks, and voted accordingly. Yes, his colleague Jon Tester went in the opposite direction, but while senators represent entire states, different senators are tied to different interests and communities. Tester, unlike Baucus, has a strong links to progressive, internet-based activists — otherwise known as the “netroots.”

If there’s a real reason to disparage Baucus, it’s his decision to extend “Gang of Six” negotiations over health care reform for three months in 2009. Meant to give time and cover for a bipartisan agreement, the effort failed. Yes, Olympia Snowe voted to bring the health care bill out of committee, but afterwards, no Republican supported passage. If anything, the long process gave wind to conservative opponents of health care reform, giving them time to build strength and momentum. By the end of the process, the public ended up with a negative attitude toward the full reform package, a problem which continues to dog the president.

Which means that, in his final term, Baucus will have left a mixed legacy. Yes, he helped build one of the most expansive pieces of domestic legislation since the Great Society, but in his caution—characteristic of red state Democrats—he helped empower the forces that want to dismantle it.

Jamelle Bouie is a staff writer at The American Prospect, where he writes a blog.