On May 5, the Oregon Business Association announced it had secured a famous voice to address its annual Statesman Dinner in Portland.

Mara Liasson, national political correspondent for National Public Radio, would deliver an Oct. 20 speech titled "Making Sense of the American Political Cyclone."

But soon it was Liasson, a 27-year NPR veteran who served as White House correspondent for eight years, who was caught in a whirlwind. Less than a week after OBA announced the speech in a press release and on social media, NPR abruptly canceled it, after receiving a complaint from the president of Oregon Public Broadcasting.

NPR's standards editor, Mark Memmott, told the business group Liasson could not appear because NPR prohibited employees from delivering paid speeches to organizations that do political advocacy.

Two members of OBA's board, speaking to WW on condition of anonymity, say Memmott told the business group that its lobbying on one issue in particular had troubled NPR enough to pull Liasson.

That issue? Initiative Petition 28, the November ballot measure that would raise $3 billion a year in new taxes on corporations with Oregon sales of more than $25 million a year. OBA is organizing business opposition to the measure.

Liasson, OBA president Ryan Deckert and an NPR spokeswoman all declined to comment on the reason the speech was canceled or how much she was to be paid. NPR spokeswoman Isabel Lara initially told WW that Liasson had declined OBA's invitation to speak, but Deckert says they had a deal. "We never announce a speaker—ever—that we don't have written confirmation or a signed contract with," he says.

The cancellation was triggered by a complaint from OPB CEO Steve Bass. OPB is a member station of NPR, paying fees to broadcast its national programming.

Bass says he learned about Liasson's speech from a mass email, and wrote to NPR asking why it hadn't notified OPB about Liasson's speech to a lobbying group. "I didn't mention IP 28 specifically," Bass says, "but did say that there could be issues on the ballot on which OBA would be actively engaged."

The cancellation is significant for at least two reasons. First, it suggests how fraught the emerging battle over IP 28 has already become. Second, it raises questions about the standards NPR has for when and where its personalities can give paid speeches.

The OBA, a bipartisan lobbying group founded in 1999, includes leaders of the state's largest companies, including Intel and Nike. Its annual Statesman Dinner has a history of distinguished speakers, including former U.S. Sen. John Edwards (D-N.C.), House Speaker Paul Ryan (R-Wisc.) and former Secretary of Education Arne Duncan.

The group is leading the fight against IP 28—a battle that pits business leaders against labor unions, which back the initiative. OBA will help raise a $20 million war chest to oppose the measure, which would impose a gross receipts tax on corporations that generate more than $25 million a year in Oregon sales. The tax will raise $3 billion a year.

Experts anticipate total spending on both sides of the measure could surpass $30 million, which would make it the most expensive ballot measure in Oregon history.

The cancellation highlights the potential ethical pitfalls of journalists giving paid speeches.

"It may be common, or is certainly becoming common, for media 'personalities' to give paid speeches for politically inclined organizations," says Tom Bivins, who teaches media ethics at the University of Oregon. "However, if one considers oneself a journalist, one should tread very cautiously in these areas."

NPR's ethics handbook says correspondents can "accept honorariums, paid travel and meals for speaking engagements and awards ceremonies, but only from educational or nonprofit groups not engaged in significant lobbying or political activity."

Lara, the NPR spokeswoman, says the policy applies only to paid, not unpaid, speeches.

Nevertheless, Shankar Vedantam, an NPR science correspondent, was paid to give the keynote address at OBA's Statesman Dinner in 2014. (Vedantam's 2014 speech came just weeks before voters rejected Measure 90, the open-primary ballot measure that was a top priority for the OBA.)

And Liasson has given speeches in recent years to at least six organizations that spend large amounts on lobbying. She was paid to deliver at least one of those speeches—given to the National Potato Council in February, according to a representative of the organization. The council has a political action committee and lobbies consistently for political causes.

In 2011, according to NPR's own reporting, the potato council waged a fight against the U.S. Department of Agriculture's plan to limit potatoes in school lunches, and between 2013 and 2015 it spent a combined $620,000 lobbying for reform in agriculture, the food industry, trade and immigration.

When presented with evidence that Liasson had previously made other speeches to lobbying groups and Deckert's assertion that the OBA had a signed contract with Liasson, NPR refined its story.

Lara, the NPR spokeswoman, says the vetting process at the radio nonprofit has been inconsistent.

"Ms. Liasson has a speakers' agency that sometimes books speaking engagements for her," Lara says. "There have been times when the agency has booked events and she did not put them through the NPR review process. We are taking steps to ensure that will not happen again."

On June 14, the OBA announced Liasson's replacement for the Statesman Dinner: Ron Brownstein, political director of magazine publishers Atlantic Media Company.