The 2012 Republican race has largely been shaped by the Republicans who declined to run. Mitt Romney has run a very smart and competent campaign, but he has also been unusually fortunate in that his competition over the last year has been almost comically inept. Here are the people conservatives can blame if Romney ends up winning.

1. George W. Bush

More than anyone else Bush is responsible for decimating the ranks of qualified Republicans who could take on Obama. A successful Presidency can produce a new crop of future Presidential candidates for the party that controls the White House. The vice president and cabinet officials, as well as governors and senators elected over the course of the administration, are historically major sources for a party’s next round of candidates. The Bush years had the opposite effect. It was unthinkable that his vice president would run for higher office and much of his cabinet left Washington tainted by the President’s unpopularity. Moreover, Bush helped sink his party in the 2006 and 2008 elections, thus depleting the ranks of potential Republican candidates for 2012.

The Republican Party rebounded in 2010, but it will take longer than two years for many Presidential-caliber candidates to emerge after the wreckage of the late Bush years.

2. Michele Bachmann

In hindsight, Bachmann had only one important role in the campaign: in August, she forced Tim Pawlenty, who was potentially Romney’s toughest competitor, out of the race. First, Bachmann attacked Pawlenty in an important debate, and then she defeated him at the Iowa Straw Poll, on which he had staked his candidacy. It was especially bitter for Pawlenty that Bachmann caused his demise. Back in Minnesota, she had made his life difficult when he was governor and she was a rabble-rousing legislator forcing anti-gay marriage measures onto his agenda.

3. Cheri Daniels

The wife of Indiana Governor Mitch Daniels reportedly halted her husband’s Presidential ambitions on the eve of his entry into the race over concerns about their privacy. (Given what it’s like to run for President, who can blame her?) Candidates often appear stronger when they are sitting on the sidelines, but Daniels did seem to have the potential to consolidate a large bloc of Republicans behind his candidacy. Ideally, a successful Republican candidate will have a mix of three characteristics: electability, conservative credentials, and a respectable resume. Daniels had all three.

Of course, there were many others who also declined to run, including Jeb Bush, Mike Huckabee, Chris Christie, Haley Barbour, Sarah Palin, George Pataki, Paul Ryan, John Thune, and Rudy Giuliani. In the absence of Daniels and these other high-profile Republicans, Texas Governor Rick Perry decided he could fill the vacuum left by their timidity. He had a great resume and a fairly solid conservative record, but was found lacking after a series of embarrassing debate performances. (He still has one last chance to make an impact in the race in the South Carolina primary.)

4. Barack Obama

Jon Huntsman is making his last stand in New Hampshire, and there is some upward movement for him in the polls. But if he doesn’t defeat Romney there (or at least come in a close second), we can trace Huntsman’s loss to his decision to accept Barack Obama’s offer to be ambassador to China in 2009. That single decision transformed Huntsman from a successful, popular governor from the most conservative state in the country into an employee of Obama, the most despised figure among G.O.P. primary voters.

5. Justice Anthony Kennedy

With so many potential candidates declining to run, and with the decline of the three Republican governors who did end up in the race (Pawlenty, Perry, and Huntsman), Romney was left facing a talk show host (Cain), a defeated senator (Santorum), a former House Speaker who resigned in semi-disgrace (Gingrich), and two of the most extreme members of the House of Representatives (Bachmann and Paul). These kinds of fringe candidates and ex-politicians trying to revive their careers run every four years (think Mike Gravel and Dennis Kucinich on the Democratic side in 2008), but they are not the kind of people a party nominates for a Presidential race.

And yet, given the populist sentiment seizing the Republican party, perhaps 2012 could be the year for one of these far-right outsiders to win. If that doesn’t happen, conservatives can partially thank the Supreme Court and specifically Anthony Kennedy, the swing vote on the court that decided the 2010 Citizens United case. “We now conclude,” Kennedy wrote for the majority, “that independent expenditures, including those made by corporations, do not give rise to corruption or the appearance of corruption.”

With that opinion, Kennedy and the court gave rise to the so-called Super PACs, political groups that raise unlimited money from individuals, unions, and corporations and which greatly advantaged Mitt Romney in Iowa, where a Super PAC that supports him pilloried Gingrich with millions of dollars in negative advertisements. The court’s decision, championed by conservatives, seems to have shifted the balance of power in the Republican primaries away from grassroots candidates who rely on a wide base of small-dollar donors to the establishment candidate, who benefits from seven-figure ad campaigns with the help of a few hyper-wealthy allies.

In other words, if Romney wins, conservatives have only themselves to blame.

Photograph by Justin Sullivan/Getty Images.