Tim Pawlenty is trying to break through the pack and become the not-Romney contender for the 2012 Republican presidential nomination. To that end, he delivered a major economic speech in Chicago.

First, the positive points. He is staking out an aggressively conservative position on taxes:

American businesses today pay the second highest tax rates in the world. That’s a recipe for failure --- not adding jobs and economic growth.

We should cut the business tax rate by more than half. I propose reducing the current rate from 35% to 15%.

But our policies can’t just be about simply cutting rates. They must also promote freedom and free markets. The tax code is littered with special interest handouts -- carve-outs -- subsidies -- and loopholes. That should be eliminated. . . .

But just changing business tax rates isn’t enough. That’s because we know most job growth will come from small and medium size businesses. Typically structured as S corps or LLCs. And their owners are taxed under individual tax rates. Not corporate tax rates.

So -- pro-job and pro-growth tax reform -- must include individual tax reform as well. Small business owners and hard working Americans need a better deal too. Small businesses should also have the option of paying at the corporate rate.

On the individual rates we need a simpler -- fairer -- and flatter tax system overall. I propose just two rates -- 10% -- and 25%.

Under my plan -- those who currently pay no income tax would stay at a zero rate. After that -- the first fifty-thousand dollars of income or one-hundred thousand for married couples -- would be taxed at 10%.

Everything above that would be taxed at 25%. That’s it.

A one-third cut in the bottom rate. To allow younger -- middle -- and lower-income families to save and build wealth. And a 28% cut in the top rate -- to spur investment and job creation.

In addition -- we should eliminate altogether the capital gains tax -- interest income tax -- dividends tax -- and the death tax. Government has no moral or economic basis to claim a second share of the same income.

It will be hard to get to the right of him on taxes.

Second, he stakes out ground as a free trader, calling for ratification of the three free trade agreements still pending and for new bilateral negotiations on other deals.

And he takes strong positions on regulations and policies that impede growth:

Under ObamaCare’s individual and employer mandates -- America’s private health care market is in intensive care. And the prognosis is bad.

The Dodd-Frank financial regulation bill called for more than 200 new rules. To be written by more than ten federal agencies. None of them resolving the catastrophic scandal of Fannie Mae and Freddie Mac.

Months after the law went on the books -- no one yet knows exactly what the law is.

And the Environmental Protection Agency -- is now regulating carbon emissions. A policy rejected by Congress -- but putting millions of jobs at risk.

If these policies sound as though they were written by people who have spent no time outside government -- well -- you’re right. President Obama’s political appointees have been notorious -- for their lack of private sector experience.

This is unacceptable. . . . .

And we don’t need the unelected officials at EPA -- to do what our elected officials in Congress have rejected. We need less EPA monitoring of our economy. And more monitoring of EPA’s affects on our freedom.

I will require sunsetting of all federal regulations. Unless specifically sustained by a vote of Congress. Under my administration -- the NRLB will never tell an American company where they can and cannot do business.

But the speech was not fundamentally as serious and as mature as Pawlenty will need to be. Most important, his spending plans are rather vague and gimmicky.

The best way, and possibly the only way -- to ensure fiscal discipline is to put the Congress in a spending straightjacket.

That’s why I support a constitutional amendment. That not only requires a balanced federal budget. But also caps federal spending as a percentage of our economy. Around the historical average of 18% of GDP.

Only a constitutional amendment has the power to bind future Congresses to keep their promises. Force decision-makers to finally make decisions. And give statutory reforms a chance to succeed.

But passing a constitutional amendment will take awhile. And the crisis that we face is here now. And requires immediate action.

I have and will continue to outline specific proposals to reduce spending -- reform government -- and balance the budget. As mentioned I’ve already begun that process. With proposals regarding ethanol -- entitlements -- government employees -- and Wall Street.

For example -- I’ve proposed capping and block-granting Medicaid to the states. Raising the Social Security retirement age for the next generation. And slowing the rate of growth in defense spending.

But we can’t trust Congress to do it. We cannot allow the situation to risk being unresolved. And take down America’s potential for growth and prosperity.

So -- I propose that Congress grant the President the temporary and emergency authority. To freeze spending at current levels. And impound up to 5% of Federal spending. Until such time as the budget is balanced. If they won’t do it --- I will.

As an example -- cutting just 1% of overall federal spending for 6 consecutive years -- would balance the federal budget by 2017.

Does he imagine even a Republican Congress will give him impound authority? And is he going to cut 1 percent across the board, and if not, what gets cut more so we can spend more elsewhere? If you want an 18 percent cap, you have an obligation to say what is going to be eliminated and trims.

At times, he sounds too cute by half: “We can start by applying what I call ‘The Google Test.’ If you can find a good or service on the Internet. Then the federal government probably doesn’t need to be doing it.” Student loans? A space program? An FDA? “The Google test” is a soundbite, not a coherent philosophy.

And finally, I love tax cuts as much as the next conservative, but it takes a leap of imagination to suppose that the huge tax cuts are going to generate such growth as to come close to generating revenue sufficient even for a sharply pruned federal government. In sum, this may be an attractive pro-growth plan, but it is not a very serious budget policy.

Mitt Romney may be a flawed front-runner, but Pawlenty is going to need to step it up to persuade Tea Partyers and other savvy fiscal conservatives that he is a credible not-Romney. They are sophisticated enough to smoke out a phony Obama budget, and they are going to want to know with a lot more specificity what Pawlenty would offer and how he is going to get from here to there — from massive debt and anemic growth to fiscal sobriety and robust growth.

And a final but important note. At one point, he said that if Obama’s policies aren’t changed, “We are in deep doo-doo. We are in deep crap.” Not presidential, not appropriate. You don’t show the base you are a tough guy by talking like a pre-teenager; you do it by developing a well-crafted and sober policy agenda that is more realistic and more in tune with American values than the president’s. Pawlenty still has time to do it, and, as evidenced by the speech, solid conservative instincts. But today’s effort isn’t going to cut it.

UPDATE (2:15 p.m.): I agree with Jim Pethokoukis of Reuters, who had this to say on Pawlenty’s goal of 5 percent growth over 10 years: “I don’t think the American economy ever managed that in the 20th century. . . . I am glad he set a high goal, but in terms of getting the debt under control, I would prefer he set a more conservative forecast.”