Ron Paul announced yesterday that he will not seek re-election to his House seat in 2012 and instead will focus on his presidential campaign.

Paul’s Congressional career, which began in 1976 and spanned 12 terms, is thus drawing to a close. David Weigel provides a retrospective on his years in the House:

Paul will leave Congress next year as arguably the most intellectually influential member of the House of Representatives in a generation. (I write “arguably” even though trying to think of a runner-up is a deeply depressing task.) He was not necessarily a successful legislator. But his career has been remarkable for its consistency.

Starting with an uphill campaign for Congress in 1974, through a wilderness period where he won the Libertarian Party’s presidential nomination, and continuing with a 1996 comeback that the mainstream GOP opposed, Paul advocated the same economic and foreign policies for 37 years. A call to abolish the Federal Reserve, a campaign to return to the gold standard, a belief that America’s foreign interventionism was illegal and unsustainable: Some of his positions remain on the fringe of politics, but others have proved remarkably popular in America’s center-right party.

When he ran four years ago, however, Paul didn’t have any ideological competition. He was solo and sui generis. It was part of his quirky appeal. Now, there are plenty of Republicans who can call themselves his successors, and as long as Barack Obama is president, Paul’s ideas are rolled into the GOP’s double helix. Ron Paul used to be alone in saying no to everything, doubting that the elites were telling the truth. Now, there are plenty of other Republicans who think that way. …

So why did he decide to retire from Congress? The Week has compiled a roundup of opinion on the subject, falling into four categories: “He’s passing the torch to a new generation,” “He hates his job,” “His Congressional district was just eliminated,” and “Paul is going all-in to win the White House.”

TAC contributor Jim Antle offers his take: “By abandoning his House seat, Paul hopes to put all his money, attention, and personnel into the presidential race. That frees up time, resources, and staff for campaigning.” Paul thus has an opportunity to avoid the mistakes of his 2008 campaign and deliver his message through a more focused and professional organization.

Paul campaign insiders believe they have an opportunity to make a statement in the 2012 presidential race. The issues environment, with its focus on debt and government growth rather than war and peace, is more favorable. The field is weaker. Paul’s son Rand recently demonstrated that Paulite arguments can be framed in a way that appeals to a broader range of Republicans.

Whatever the outcome of his presidential campaign, Paul’s influence will continue to be felt in the Tea Party that he helped to inspire, among a cadre of youthful activists, and within a Republican party that is newly receptive to his ideas on spending, war, and constitutionalism—an impressive legacy for a “fringe” politician.