The big mystery in President Obama’s now-released interview with the editorial board of The Des Moines Register is why the president wanted it to be kept under wraps in the first place.

In the transcript, released by the White House after Obama was criticized in a blog post by the newspaper’s editor, Obama came across as a big-thinking candidate with a plan for the next four years if he is re-elected. He defended his record and drew contrasts with his opponent in clear terms, without the bitter wisecracks that have become standard fare on the campaign trail.

According to the transcript, Obama wants to expand the strategy that saved the domestic auto industry to other industrial sectors, bringing manufacturing jobs we have lost back to our shores. He spoke about revising the tax code to reward companies that make things domestically because growth in manufacturing jobs creates jobs throughout the economy, including the service sector.

He repeated his pledge to get control of our own energy supply by continuing to invest in the development of biofuels and renewables. Some of them won’t pay off immediately as an alternative to fossil fuels, but they have lower environmental costs and in the long run would be worth the investment.

“The country that controls new sources of energy, not just the traditional sources, is going to have a huge competitive advantage 10 years from now, 20 years from now, 30 years from now,” Obama said.

When asked why he used political capital on health care when unemployment was still at crisis levels, Obama countered that Congress did pass a historic stimulus that kept the recession from being much worse (with only three Republican votes, including those of both Maine senators), but there was no sign that Republicans or even some Democrats would have voted for more. Health care is one-sixth of the economy, and health care inflation creates much of the out-of-control growth in government spending. It made sense to reform health care, the president said, and the program will be more popular when people see it is not as bad as they were led to believe.

And Obama played pundit, saying that if he wins re-election it will be because Republicans have alienated Hispanics, the fastest-growing ethnic group in the country. That alone should end their intractable opposition to comprehensive immigration reform that has paralyzed Washington from taking the action that most Americans support.

Obama came across as confident and optimistic about what would await the country if he is returned to a second term. Our economy is already growing faster than Europe’s or Japan’s, and the elements are in place to create the virtuous cycle that would lead to more private investment and faster growth.

Campaigns should be made up of these kinds of interviews, instead of the barrage of poll-tested sound bites that dominate candidates’ appearances and even the televised debates.

As the final days roll out, the contenders are after ever-smaller slices of the electorate, microtargeting their messages to tiny subsets of the country.

This is why the Des Moines Register interview is such a relief. We are grateful that they didn’t keep it a secret.