“This is not a budget,” Paul Ryan said as he introduced the Republicans’ 10-year budget plan. “This is a cause.”

Truer words have never been spoken.

The document released by the chairman of the House Budget Committee isn’t a serious budget proposal because it fails at the central mission of ending the deficit and taming the debt.

Without question, Ryan makes some severe cuts: Taking hundreds of billions of dollars from Medicaid, ending the Medicare entitlement and slashing planned spending on transportation, energy, education, veterans benefits, agriculture payments, counterterrorism and more.

Yet for all these cuts, the Republicans’ plan increases the federal debt by more than $8 trillion over the next 10 years, and it continues federal budget deficits until nearly 2040. Under the proposed balanced budget amendment to the Constitution that Ryan and his Republican colleagues claim to support, Ryan’s budget wouldn’t be in compliance for at least the next quarter-century.

How could the House Republicans make such enormous cuts and yet not solve the debt crisis? Simple: Ryan’s proposal isn’t a budget. It’s a manifesto for the anti-tax cause. The GOP plan reduces the government’s revenues by $4 trillion over 10 years because of tax cuts, including a lower top rate for businesses and the wealthy.

On Tuesday, Ryan claimed that the White House’s 2012 budget proposal was a punt, and he’s correct. President Barack Obama’s budget was irresponsible, failing to take on entitlements and relying on rosy assumptions. But Ryan’s budget is equally irresponsible. He punts on Social Security and proffers silly forecasts of his own – including a Heritage Foundation claim that Ryan’s plan would reduce unemployment to 4 percent in 2015 and 2.8 percent in 2021.

Worse, Ryan insists that virtually all the pain comes from the Democrats’ beloved social programs, while leaving defense spending untouched and requiring little sacrifice from wealthy taxpayers.

Had he been serious about reaching a budget agreement, Ryan would have offered something along the lines of the proposal of the Bowles-Simpson commission, on which he served. Using a combination of tax increases and spending cuts, commissioners devised a formula that would reduce deficits by $4 trillion through 2020, stabilize the debt by 2014, and keep Social Security solvent for 75 years. A bipartisan group in the Senate is working to draft a similar compromise.

But Ryan, who dissented from the commission recommendations, seems more interested in having a fight over this during the 2012 campaign than in working out an agreement. Asked at a news conference Tuesday whether any of his proposals might be enacted before the election, he replied, “At the end of the day we might just have to have a debate or a decision in this country about two futures.”

An hour later, Ryan offered a variation on the theme in a speech to the American Enterprise Institute: “If we don’t get agreements in the intervening time because of politics or whatever, at least in 2012 they’ll have a real choice.”

Democrats, no doubt, would be happy to engage in that campaign. They’d enjoy pointing out that, in 2016, Republicans would cut Obama’s proposed education spending by 36 percent and his transportation spending by 41 percent. They could point out that Republicans would take $19 billion from veterans and zero out energy spending.

Democrats could also argue, as the Congressional Budget Office does, that the proposal to turn Medicare into a private program using voucherlike payments would lead to higher out-of-pocket costs. This would inevitably force more elderly into nursing homes, but Ryan also takes $771 billion over 10 years from Medicaid, about half of which pays for nursing-home care of the elderly, according to the Center for American Progress’ Scott Lilly. Does Ryan want to see Democrats’ ads on TV saying Republicans would cast poor seniors into the streets?

“What do you say to nervous Republicans who say that this is a political kamikaze mission?” ABC News’ Jonathan Karl asked Ryan. Had the chairman “just given Democrats a big target that may ultimately cost Republicans your majority?”

“They didn’t come here for a political career,” Ryan replied. “They came for a cause.”

If that cause were to vanquish the deficit, then a solution is already at hand. “If you didn’t go as far as you went in terms of cutting taxes,” CNN’s Dana Bash asked Ryan, “couldn’t you balance the budget faster?”

Ryan allowed that this is true – “on paper.”

But doing the responsible thing on paper is so much less fun than storming the ramparts for a cause.