Less than a week after describing the implementation of Obamacare as “a huge train wreck coming down,” one of the law’s chief architects — Senator Max Baucus (D., Mont.) — announced he would not seek reelection in 2014.

The move came as a surprise to many. The six-term senator was one of four Democrats to vote against the Toomey-Manchin gun-control bill last week, which seemed to suggest that the senator had an eye toward reelection, especially given that his recently elected colleague Jon Tester (D., Mont.) had supported the bill. Baucus told reporters that last week’s vote “had nothing to do” with his decision to retire. His fellow Democrats, though, were reportedly caught off guard; some were angry.

Republicans were somewhat less surprised. With Obamacare proving increasingly problematic to implement, they are hoping to make it a key issue in their campaign to retake the Senate in 2014; Baucus, who chairs the Senate Finance Committee and was the lead sponsor of the Obamacare legislation, would have been a primary target. This was likely a driving factor behind the senator’s decision, Republicans argue.

“Vulnerable Democrats will face voters just as Obamacare’s tax hikes, mandates, fees, penalties, and red-tape bureaucracy take shape over the next eight months, and Senator Baucus’s retirement reflects that political reality,” said Rob Collins, the executive director of the National Republican Senatorial Committee, in a statement.

“Baucus signed his own pink slip when he decided to play an instrumental role in not only crafting but passing Obamacare into law, and he wouldn’t want to have had to answer for that every day on the campaign trail,” a GOP Senate aide tells National Review Online. “Max Baucus is as essential to Obamacare as a ball is to a game.”

In a statement announcing his retirement, Baucus said it was “an extremely difficult decision,” but he ultimately wanted to serve out the remainder of his term “unconstrained by the demands of a campaign.”

There is some buzz on Capitol Hill about what Baucus’s retirement could mean for the prospects of comprehensive tax reform. House Republicans appear eager for progress on the issue, and the Senate finance chairman had expressed a similar willingness. GOP aides quickly shot down the notion that Baucus’s decision would make tax reform more likely. “I don’t think he was ever serious about that,” one aide says. “He was a guy who was out for himself.” Not to mention his impressive collection of former staffers turned lobbyists, many of which were already lining up to influence possible tax-reform legislation.

Baucus was notorious for his ties to K Street and his willingness to use his position as finance chairman to reward clients of his former employees. The “fiscal cliff” agreement signed earlier this year included language approved by Baucus’s committee that provided significant tax breaks to companies such as General Electric, where his former chief of staff Peter Prowitt works as an executive director of government relations. Former finance committee chief counsel Michael Evans helped secure the extension and expansion of biofuel tax credits for his clients in the algae industry. The American Wind Energy Association successfully lobbied to save tax credits for wind producers with the help of former Baucus adviser Shannon Finley. “There are former Baucus staffers lobbying the federal government as far as the eye can see,” says a GOP Senate aide. “If anyone’s mourning this retirement announcement, it’s them.”

Baucus’s connections to industry lobbyists, however, did not necessarily translate to influence for Baucus within the Senate. Republicans suggest that Democratic leaders simply exploited him at times when those connections were needed. “They used his influence and lobbyist connections to push Obamacare through the Senate, but it’s sort of sad the way they’ve treated this guy for the most part,” says the GOP Senate aide.

Earlier this year, Baucus urged Patty Murray (D., Wash.), the Senate budget chairman, not to include reconciliation instructions for tax reform in her budget resolution (Murray’s “tax reform” consists solely of closing loopholes for rich people and large corporations). Because budgets cannot be filibustered in the Senate, including these instructions would allow Democrats to jam through tax legislation by a simple majority vote, but under strict parameters — each individual change in the tax code must be scored as not adding to the deficit. Baucus favored a more flexible and deliberative process via the finance committee, which has experience writing tax legislation, to take on reform of the entire tax code, rather than make minor adjustments to the current code as Murray proposed. Additionally, the reconciliation approach would be sure to alienate Republican senators who might otherwise be open to working with Baucus. But after weeks of protesting, he was ultimately ignored. His office blasted the decision in a statement to Breitbart News, saying: “Reconciliation would kill the possibility of doing any tax code simplification.”

More recently, Senate majority leader Harry Reid (D., Nev.) skirted the finance committee altogether by bringing Internet-sales-tax legislation to the floor earlier this week, over Baucus’s strong objections. And hours after Baucus voted against gun-control legislation last week, President Obama accused him of having “caved to the pressure” of the gun lobby and its allies, who “willfully lied” to the American people. “Kind of a sad way to end a very long career on the Hill,” says the GOP aide.

— Andrew Stiles is a political reporter for National Review Online.