Colorado liberals spent a decade and millions of dollars pushing their state's political agenda to the Left. Although the Centennial State's unique constitution has frustrated the Democrats' appetite for higher taxes, they have largely succeeded in most other areas. They have elected legislators who backed ill-advised mandates for renewable energy use, constitutionally questionable gun control measures and other laws that please rich liberal elitists in Aspen and Denver but perplex and frustrate everybody else.

Next month, the liberals will take another step by submitting the required number of signatures to place two anti-fracking measures on the fall ballot as state constitutional amendments. This has many of the state's top Democratic politicians running in fear from a battle that Democrats everywhere will soon have to confront.

Gov. John Hickenlooper and U.S. Sen. Mark Udall -- two of the most prominent Democrats facing re-election this fall against credible GOP opponents -- oppose the constitutional amendments, which are bankrolled by their partisan colleague, U.S. Rep. Jared Polis. The issue is fracturing the state's Democratic Party, whose delegates added an even more radical anti-fracking position to their party platform in April and whose legislators refused a compromise that could have averted this fight.

Oil and gas industry groups say Polis' measures will cut their business in half. They have vowed to spend $20 million fighting them, and the Democratic establishment is terrified that many of their statewide candidates will be hit in the crossfire. National Democratic leaders should worry, too, because a Udall defeat could put Republicans in control of the U.S. Senate.

Thanks to fracking, oil and gas are now a $29.5 billion annual business in Colorado. The industry accounts for more than 10 percent of the state's gross domestic product and 111,000 jobs. But this is not just a Colorado issue -- it is also an issue in several politically competitive states like Michigan, Pennsylvania and Ohio. It's a national issue, too.

Fracking has boosted America as the world's leading energy producer. The U.S. will soon surpass Saudi Arabia as the world's top oil producer. The energy revolution produced by fracking is saving money for private households, school districts and governments across America. It is also probably the only thing separating the current Obama “recovery” from the sixth year of what would otherwise be a Second Great Depression. Fracking is also making America more energy independent just when President Obama and Secretary of State John Kerry seem incapable of protecting U.S. national interests overseas.

The fight in Colorado could be repeated in many states with energy resources. Some voters will choose a technologically advanced nation in which each generation improves its economic lot over the last. Others will side with radical environmentalists who obsess about ridding America of all fossil fuels and even repealing the industrial revolution. Perhaps Udall's choice of the right side on this issue won't merely be an election dodge. Other vulnerable Senate Democrats facing voters in November may also have to choose.