President Obama’s speech today attacking Paul Ryan’s budget seemed designed to accomplish three key political objectives. They added up to a broad election-year indictment of the Ryan-Romney vision, and staked out his offering in a big ideological argument that will determine the outcome of the 2012 elections.

1) Obama cast the Romney-Ryan-GOP approach as not only radical and extreme, but as a proven failure. It’s likely Mitt Romney will easily clear the basic competence threshold of voters; his abilities and leadership qualities will likely be more established than John McCain’s in 2008. So a great deal will ride on whether Obama can persuade voters that the Ryan-Romney policy/ideological approach has already been tried and has been a miserable failure.

Obama offered his most extensive effort to do this of the cycle. He noted that tax cuts for the rich under Bush were supposed to produce massive job growth, but didn’t; that trickle down economics was supposed to lead to broader prosperity, but didn’t; and that cutting government regulations can have actual consequences, such as dirtier air and water and less worker safety, and can lead to greater risk of financial disaster. “We tried their approach on a massive scale,” Obama said. “The results of their experiment are there for all to see.”

2) Obama defended government activism as not just morally right, but as a way to faciliate economic growth. Obama has long defended government’s role in combatting inequality, preserving the safety net, and investing in the country’s future. But today he made perhaps his lengthiest case yet that such government activism is necessary to spur economic growth, too. It’s a case he hasn’t made as effectively in the past, but it will be crucial in rebutting GOP claims that liberal governance is to blame for our economic travails.

He buttressed this argument with allusions to a string of accomplishments by Republican presidents, including Dwight Eisenhower’s interstate highway system and investmentments in scientific research, and other more recent achievements. “What leaders in both parties have traditionally understood is that these investments aren’t part of some scheme to redistribute wealth from one group to another,” Obama said. “These investments benefit us all. They contribute to genuine, durable economic growth.”

The message: In opposing public investments on things like infrastructure and education, today’s GOP leaders are departing from longtime bipartisan consensus about the desirability of collective action to build our economy and lift the country.

3) Obama framed the choice as one over who sacrifices to fix the deficit. Majorities of Americans favor higher taxes on the rich, but it’s unclear how much this actually motivates voters. Obama needs to vividly spell out to the American people that the push for higher taxes on the wealthy is at bottom about who will do the sacrificing to fix the country’s fiscal problems. If the wealthy don’t sacrifice a bit more, or if we give the rich still more tax cuts, the elderly and beneficiaries of government services will have to do all the sacrificing.

“If you want to keep these tax breaks and deductions in place, or give even more tax breaks to the wealthy, as the Republicans in Congress propose, either it means higher deficits, or it means more sacrifice from the middle class,” Obama said. Obama’s push for tax fairness will turn on how effectively he makes the case that the GOP’s approach wouldn’t actually bring down the deficit without sacrifice from somebody.

In sum, the political case he made is threefold: The GOP approach has already failed us. In its current, more radical iteration, it’s a departure from longtime consensus about government’s proper role in spurring economic growth and in guarding against the excesses of unfettered capitalism. And that addressing inequality and tax unfairness isn’t just morally right; it’s the only way to secure the country’s future.