Washington ? John McCain’s undeclared but ubiquitous presidential campaign will produce a delicious moment when he announces, as he surely will, that he will not participate in the public funding system for presidential primaries. And if he is nominated, he and his Democratic opponent probably will be the first nominees since 1972 to rely on private money in the general election campaign.

There are two compounded ironies. First, the mantra of campaign “reformers” is that there is “too much” money in politics. But McCain will shun public funding because it provides too little money. He can raise much more from private interests. (But not from “special interests,” which are interests McCain disapproves of.)

Second, the reformers revere the McCain-Feingold legislation that expanded government regulation of the quantity, timing and content of political speech. But McCain-Feingold is one important reason why the public funding system is collapsing.

That legislation banned large contributions of “soft money” – money that can be used for party-building and other activities but not for specific candidates’ campaigns. It also doubled from $1,000 to $2,000, and indexed for inflation, the size of contributions of “hard dollars” that candidates can receive. This doubling made it even easier than it already was to raise more money than the public funding system could provide to presidential candidates, even if the public were fully funding the system. Which the public emphatically refuses to do.

Candidates accepting government subsidies in the primaries can spend only stipulated sums in particular states: Our amazing government knows precisely the right amount for each state, and knows that the same sum will be suitable for all candidates’ campaign needs. In 2004, candidates accepting taxpayer subsidies were restricted to spending a total of just $45 million in all the caucuses and primaries and the rest of the pre-convention period. George W. Bush’s and John Kerry’s campaigns, spurning the subsidies, each spent more than five times that amount before the conventions.

Taxpayer financing of presidential campaigns, an entitlement program for the political class, was enacted in 1974 as that class’ response to Watergate. Taxpayers were given the power to direct, by a checkoff on their income tax form, $1 of their tax bill to the fund.

Why does the political class use this sneaky approach rather than a straightforward appropriation for itself? The question answers itself.

Even though the checkoff does not increase the individual’s tax bill, support peaked in 1981 when 28.7 percent of taxpayers used it. So even then it was opposed by more than 70 percent of taxpayers. In 1994, Congress responded by increasing the checkoff’s value to $3. This empowered fewer people to divert more money from the government’s pool of revenue collected from all taxpayers. All this to fuel a program opposed by the vast majority of taxpayers, a program that subsidizes political advocacy that most taxpayers do not endorse.

Because by now 90 percent refuse the $3 checkoff, the Federal Election Commission, which has a bureaucracy’s metabolic urge for self-aggrandizement, lobbied the largest manufacturers of tax preparation software to take two measures to promote the checkoff system.

Hitherto, the companies’ software, reflecting their customers’ obvious preference, used “no” as the default option. But the FEC got the companies to change that, and to include an advertisement for the checkoff, saying it “reduces candidates’ dependence on large contributions from individuals and groups and places candidates on equal footing in the general election.” That bit of puffery is simplistic to the point of tendentiousness: Large hard-dollar contributions (larger than $5,000) are illegal, and there is much more to “equal footing” than hard-dollar equality in the post-convention sprint to Election Day.

Reformers, redoubling their efforts as their goal of total public financing of all campaigns recedes, now propose measures to resuscitate what the public is trying to euthanize with nonsupport. Reformers propose yet another increase – to $5 – in the value of the checkoff, and an increase in the sums that could be spent before and after the conventions.

Government programs are immortal, so public funding of presidential campaigns will limp along, making matters worse by enabling not-even-marginal candidates (e.g., $7.2 million for Alan Keyes, $3.1 million for Dennis Kucinich) and demented and vicious charlatans ($5.4 million for Lyndon LaRouche, $3.0 million for Lenora Fulani) to clutter the process.

In 2008, Republican and Democratic aspirants who depend on taxpayer funding in the primaries will be seen, correctly, as second-tier and likely losers. McCain is neither. He is, however, the person most responsible for the perverse consequences of the government’s multiplying intrusions into what should be a free market for political speech.