Barack Obama’s decision to abandon public financing for his presidential run may finally mark the program’s doom. It should.

Reformers have long equated public financing with cleaning up elections. But “reformer-in-chief” Obama has realized public financing would reduce his cash advantage over John McCain for the fall election — and opted to rely on private money instead.

But is the good government crowd criticizing Obama? Hardly.

Reformers may not like his decision, but their real reason for demanding restrictions on money in politics was always to help liberals win elections.

Indeed, public financing of campaigns has always been more about partisan politics than the public interest.

Today’s system of public funds for presidential candidates was born in 1974, after Republicans had opened up large fund-raising leads over the Democrats in three straight presidential racs. The new rules closed the gap between the parties overnight. Some experts even credit the public-funding mandate with handing Jimmy Carter the 1976 election.

Note that the general public also didn’t react strongly to Obama’s decision. That’s no surprise. Public support for the taxpayer financing of elections has never been strong.

Consider: The money for the presidential system comes from a check-off on tax forms, which ask taxpayers if they’d like to earmark $3 of their taxes for the presidential system. And ever-fewer taxpayers are willing to check off the box to support the system.

In the late 1970s, 28 percent of filers earmarked money for it. The percentage has dropped steadily ever since; it’s now well under 10 percent.

Apart for a brief time in the 1970s, public opinion surveys have also indicated that the majority opposes public funding of campaigns.

Nor has the presidential fund shown many benefits. It hasn’t even increased the number of candidates entering party primaries — it was about the same in elections before 1976 as after. And the most successful third-party candidate after 1976 — Ross Perot in 1992 — declined public funding, and over the years, the system has produced only a tiny increase in third-party candidates.

Conspiracy theorist Lyndon LaRouche has raised millions for his many runs for the presidency, but few taxpayers would count his campaigns (especially the 1992 one, when he ran from federal prison) as a public benefit.

So taxpayers have spent over a billion dollars funding candidates since 1976, with little evidence that they’re getting more or better choices than they had before.

Obama’s campaign this year helps show why public financing is obsolete: He has proven that private donors — a large percentage of them giving only small sums — can turn a long shot into a serious contender for the White House.

If Obama can do all this, why should taxpayers be forced to fund campaigns?

Congress ought to loosen existing restrictions on political fund-raising and campaign spending. While they’re at it, our representatives should also bring the presidential public-financing boondoggle to a merciful and well-deserved end.