Climate advocates and representatives from the Rosebud Sioux Tribe in South Dakota protest against the Keystone XL pipeline in front of the home of Sen. Mary Landrieu (D-La.) in Washington. (Gary Cameron/Reuters)
Opinion writer

Here comes the tea party of the left.

On a rainy Monday morning, 50 sodden liberal activists stood on the muddy front lawn of the Capitol Hill home of Sen. Mary Landrieu, advocating for the Louisiana Democrat’s defeat.

“This house is high and dry, but the coastlines of Louisiana are sinking, very much like Senator Landrieu’s career!” Erich Pica, president of Friends of the Earth, shouted into a microphone.

The activists behind him, who had inflated a model of an oil pipeline on the senator’s lawn using a generator and a window fan, erupted in cheers of “Woo-hoo!” and “Yeah!”

“And she’s hooking her political career on the passage of the Keystone XL pipeline,” continued Pica, referring to Landrieu’s effort to force a Senate vote on the project in an effort to boost her prospects in next month’s runoff election.

Here's a look at the proposed route and some of the facts and controversies surrounding the pipeline.

“You would rather allow Big Oil to dictate the politics of this country and your reelection at the expense of . . . this country and the world, just to get reelected,” Pica charged. “Shame on you!”

I pulled aside Pica, water dripping from his nose, to ask whether he really believed that it would be better for the environmentalist cause if Republican House member Bill Cassidy — who says he isn’t even sure climate change exists — wins the runoff against Landrieu, the top Democrat on the Senate Energy Committee.

“Yeah, I think it would be good thing,” the activist said. “Even if it’s a freshman junior senator from Louisiana who’s a Republican, it ends up being better for our issues because you don’t have a leader in the Senate on energy issues fighting for more oil pipelines.”

In fact, Pica wasn’t troubled that so many moderate Democrats with “wishy-washy positions on oil and gas” lost their seats this month. He said a smaller group of uniformly liberal Democrats would help his cause, “particularly as the president is trying to push through executive orders. Having a more united Democratic caucus helps.”

I’ve heard this argument before, coming from tea party activists who said that they would rather have a smaller but reliably conservative caucus than a large majority full of RINOs — Republicans in Name Only — who aren’t reliable votes. The emerging purists on the left aren’t nearly as strong as the tea party was (and they won’t be, as long as there’s a Democrat in the White House), but it’s noteworthy that Democrats are becoming more willing to purge those who aren’t ideologically pure.

The midterm elections, a protest against Washington dysfunction, have paradoxically reinforced the problem by sweeping moderate Democrats out of the Senate (and a few who had remained in the House). Many liberals will now say — as Republicans did after the 2006 and 2008 defeats — that the way back to the majority is to be pugnaciously progressive. This will be seen with immigration and other issues, too. President Obama has shown little interest so far in compromise, and Harry Reid, becoming Senate minority leader, is a former boxer who still loves to brawl.

There were seven police vehicles outside Landrieu’s house, a double-size, red-brick townhouse with shutters drawn, pink roses still blooming in front, a New Orleans Saints door ornament and a bumper sticker in the sidelight announcing “I’m with Mary.” But they didn’t intervene, even when the activists posed for photos on Landrieu’s front steps with their “Vote No KXL” signs. A guy in a San Francisco Giants cap led a call-and-repeat chant taunting Landrieu.

Karthik Ganapathy, a coordinator of the event from the climate-change group 350, was also pleased with the prospect of a smaller, more liberal Democratic caucus in the Senate. I asked whether he saw any difference between Landrieu and Cassidy.

“If there is, it’s marginal,” Ganapathy said. “And we think the value gained in showing the Democratic Party that they need to be better on climate issues outweighs the marginal differences. . . . This is about sort of instigating a cultural shift and a political shift that sends a message to politicians that they all need to be better on climate issues.”

In other words: Be pure, or be afraid.

One of the speakers, a young woman named Maria Langholz, argued that liberals must stop Democrats from “compromising on the promises they have made.” I pointed out that her message sounded like the tea party.

“I know,” Langholz said with a laugh. But she had just returned from working on the Senate race in Iowa, where Democrat Bruce Braley, “kind of middle-of-the-road,” lost to conservative Republican Joni Ernst.

“Ernst was sticking to her guns, saying, ‘This is what I stand for,’ ” Langholz concluded, “and that really inspires people.”

Twitter: @Milbank

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