At the same time as Sen. Bob Corker, R-Tenn., wants to spend $38 billion to hire 20,000 more border agents and build a fence on the Mexican border, President Obama on Tuesday proposed to use his executive powers to override Congress and write stricter environmental rules.

Why not combine the two projects, and build a fence of solar panels along the border? That would generate renewable energy for Obama, and ensure the safety of the border.

The land boundary between America and Mexico is 1,914 miles. The total cost of building a 15-foot fence and installing solar panels would be about $12 billion. And it could face south, towards the sun.

This would make more sense than Obama's green initiatives.

In a video posted on the White House website over the weekend, Obama once more made the case for ethanol, electric cars, windmills, and solar panels.

No matter that by some measures global temperatures have not risen for the past 15 years.

Wind turbines and solar panels are imported from abroad, manufactured in China using electricity made by coal.

America's gasoline supply cannot absorb rising quantities of ethanol mandated by Congress because fuel consumption is declining.

Cellulosic ethanol, required by law to be purchased by petroleum refiners and importers, is not even produced in commercial quantities, so companies are fined for not using a nonexistent product.

U.S. greenhouse gas emissions have been declining since 2007, and fell by 1.6 percent between 2010 and 2011, the Environmental Protection Agency announced earlier this year.

The message that government can create jobs by requiring more costly technology is a siren song, seductive but empty. Yes, some Americans might be employed building the technology, but others lose jobs due to more expensive energy.

By reducing emissions through executive order, the president is stepping carefully between the blues and the greens which comprise part of the Democratic Party's fragile coalition. Blue-collar workers want jobs and economic growth, and environmentalists, who do not care about growth, want conservation and lower emissions.

Increased regulation of carbon will reduce jobs in the mining industry, harming the 74,577 members of the United Mine Workers of America. Over 100 coal-fired power plants have closed since the beginning of 2010.

The Democrats' blue-collar supporters are one reason why legislation to regulate emissions, known as "cap-and-trade" because it would have capped emissions and encouraged firms to buy and sell rights to pollute, failed to pass the Democratic 111th Congress in the first two years of Obama's term.

The bill would have required the EPA to shrink greenhouse gas allowances steadily to 2050. When any year's emissions would have exceeded a firm's cap, the firm would have to purchase allowances from the government or other companies. That is a tax under another name, driving up costs that would be passed on to consumers.

The revenues from the Kerry-Lieberman and Waxman-Markey bills, about $646 billion over 8 years, were too large for a Democratic Congress to support, even with Obama's backing. Now Obama wants to do cap-and-trade through regulation.

The president has blocked the Keystone XL pipeline, angering the blues, such as the Laborers International Union of North America. Not only would constructing the pipeline create construction jobs, but employment in Gulf refineries would expand to process oil from Canada.

LIUNA president Terry O'Sullivan said earlier this year, "The Keystone pipeline will unlock thousands of good jobs for American workers."

Raising the cost of energy at any time is poor economic policy, but especially when economic growth is 2 percent and job creation slack. Now is not the time for Obama to overrule Congress with more regulation.

DIANA FURCHTGOTT-ROTH, Washington Examiner Columnist (, former chief economist at the U.S. Department of Labor, is a senior fellow at the Manhattan Institute for Policy Research.