Landrieu has netted more than $547,000 this cycle from the oil and gas lobby in the 2014 cycle, according to data from the Center for Responsive Politics. Between individual and PAC contributions, California-based Sempra Energy has given her $47,500, while NRG Energy has chipped in nearly $46,000. The American Petroleum Institute PAC has even given $6,000, the most for any individual candidate.
That's more than double the haul drawn by her challenger, Republican Rep. Bill Cassidy. Cassidy has been on the receiving end of $203,000 in industry funding, which includes nearly $18,000 from Murray Energy and $10,000 from Koch Industries.
So how is Landrieu doing it?
Landrieu's rise to the top of the Energy and Natural Resources Committee, where she can oversee the industry that drives much of the economy in her state, has been key. She's been playing up just how important that role is; an April campaign ad featuring narration by shipbuilder Boysie Bollinger states, "Louisiana can't afford to lose Mary Landrieu."
She's also been a reliable opponent of the White House's climate agenda: Just Monday, she took to a coal plant in her home state to blast the administration's proposed emission regulations.
In an email, Sempra spokesman Doug Kline said the company supports "candidates who share our views about effective public policy and positive economic development" and that it had a good working relationship with Landrieu.
But the industry support comes as the Landrieu-Cassidy race could play a role in the balance of the Senate, a potentially bigger prize in the energy world. Republicans have vowed to make energy a priority if they retake the Senate, an agenda sure to include bills that would restrict or kill Environmental Protection Agency regulations. In an interview on C-SPAN's Newsmakers last weekend, Senate Republican Policy Committee Chairman John Barrasso said issues like the Keystone XL pipeline and natural-gas exports offered a "huge opportunity" for a Republican Senate.
And while Democrats haven't done much to promote the environment with their majority, they have beaten back efforts they say would harm the climate. That included a Landrieu-led effort to get a vote approving Keystone, a failure she blamed on Republicans.
But opponents are pointing out that those failures weaken her message of political clout and it's led her to lose a potentially powerful ally at home. Don Briggs, the head of the Louisiana Oil and Gas Association, is backing Cassidy in what is essentially a proxy vote against Majority Leader Harry Reid.
"I know Mary very well and I've always supported her personally," said Briggs, who is endorsing Cassidy personally and not on behalf of the trade group. "But changing the Senate to me is the big picture. The [Energy chairmanship] isn't very valuable if you can't do anything with it."