Big win for Steyer: Michigan Senators vote down Keystone

2015 Jeep Cherokee
Source: Chrysler
2015 Jeep Cherokee

The U.S. auto industry keeps trying to push smaller and more fuel efficient cars. But the same scenario keeps rearing its head over and over: Detroit really only does well when sales of trucks and SUV's are on the rise. And that means that a steady supply of moderately priced gasoline is essential to the Big 3, Motown, and the state of Michigan's economy overall.

That's why it seems so puzzling that while eight Democrats voted to override President Obama's veto of the bill to fully build the Keystone Pipeline, Michigan's two Senators were not among them. If Democrat Senators from states like Delaware, Indiana, Missouri, Montana, North Dakota, Pennsylvania, Virginia, and West Virginia could vote in favor of the pipeline, why didn't Democrats Gary Peters and Debbie Stabenow do it for Michigan?

Read MoreSenate fails to overturn Obama's keystone bill veto

And when you consider that most of the big labor unions are strongly in support of fully completing Keystone, the Peters and Stabenow votes become even more puzzling. Don't Democrats in the Midwest need to make those unions happy or call it quits?

Some believe that loyalty to President Obama was the key factor. But with Mr. Obama already well into his second term, loyalty to the White House is starting to wear thin. And this president will be long out of office the next time either Peters or Stabenow have to run for re-election.

So the real answer may come in the form of two words: "Tom Steyer." The billionaire investor's strong opposition to the Keystone Pipeline is well known and runs afoul of his green investment porfolio and agenda. During the 2014 Senatorial election that brought Peters into office, Steyer's NextGen Climate political action committee targeted Republican candidates who supported the pipeline. That was especially true in Michigan where NextGen successfully targeted Peters' opponent Terri Land. With Steyer's help, Peters won by a comfortable 400,000 votes out of a total three million votes cast. Steyer didn't get a big number of other victories in the big Republican 2014 midterm election year, but he did make his presence felt heavily as a key Democratic Party donor and electoral activist.

Read MoreWho's leading the 2016 presidential race? Ask futures

Peters and Stabenow aren't alone. Ohio Democrat Sherrod Brown was another "nay" vote yesterday even though his state is where the Jeep Liberty, Jeep Wrangler and the Ford Econoline van are made. And Illinois Democrat Dick Durbin voted "no" even though his state is home to the production of the Ford Explorer.

Steyer and donors like him, not to mention the long list of celebrities who see themselves as environmental activists, can make life very uncomfortable for Democrats in Congress who might otherwise work harder for their own constituents' interests. I suppose some voters in their states will be won over by a packaged message insisting these Senators were spurred to vote as they did because they really believe Keystone will badly harm the environment. Still, I wouldn't try that line in front of a crowd of unemployed former factory workers.

But Steyer looks like a winner here either way. Just because the Democrats didn't hold the Senate in the 2014 elections doesn't mean Steyer didn't grab more of a hold on the party. Yesterday's Keystone vote sends a strong message that the road to the Democratic nomination for president in 2016 may very well run through him.

Commentary by Jake Novak, supervising producer of "Power Lunch." Follow him on Twitter @jakejakeny.