Republican U.S. Sen Ron Johnson is fighting for the right of conservative talk show host and friend Vicki McKenna and others to puff away on the e-cigarettes. Credit: Rick Wood

In recent months, U.S. Sen. Ron Johnson has taken up the vaping cause, trying to stub out efforts by the U.S. Food and Drug Administration to regulate e-cigarettes.

For Johnson, the issue is personal. He has said he is fighting for the right of conservative talk show host Vicki McKenna and others to puff away on the battery-powered devices.

"You know how much I like you. I love you, Vicki, let's face it," Johnson jokes on "Keep Vapin', Vicki," a May podcast produced by his staff. "So I'm really glad that you quit smoking. I want to make sure these products are available to you and other people who've quit smoking.

"I think what the listeners just heard is an example of what extraordinary knowledge you bring to your show every day, twice a day."

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Republican Johnson, a nonsmoker who has appeared on McKenna's show 35 times in the past year (twice as many appearances as his second favorite interviewer — conservative talker Charlie Sykes), said he was put on the vaping issue by a column on The Wall Street Journal's website. As chairman of the Senate Homeland Security & Governmental Affairs Committee, Johnson likes to say that he can regulate any issue in the federal government.

In the November election, Johnson is taking on Democrat Russ Feingold, a former U.S. senator.

Johnson and McKenna got to know each other when they appeared jointly in tea party rallies in 2010. McKenna said this week that she never lobbied Johnson on the issue of vaping but was happy that the first-term senator was taking it on.

Over the past month, Johnson sent two letters to Food and Drug Administration Commissioner Robert M. Califf, asking him to justify the agency's plans to begin regulating the $3 billion vapor market beginning later this summer.

In an email, McKenna said: "I was happily surprised, and absolutely thrilled he sent the letter! It's an insane regulation that could have the effect of preventing millions of users from being able to stay OFF cigarettes."

McKenna has said she smoked up to two packs of Camel Lights a day for 23 years before opting for e-cigarettes.

"Truly," she continued, "this regulation will probably actually kill people."

The senator followed his May letter by raising more concerns about the FDA's regulations and giving the commissioner a deadline for responding to his questions. Johnson threatened to "resort to other means to compel the production of this information" if Califf failed to respond.

"His interest is in fighting peremptory federal regulations and their negative unintended consequence, such as the destruction of businesses and jobs," said Patrick McIlheran, spokesman for Johnson.

McIlheran noted that his boss has spent much more time on border security, drugs, education and other health topics than the vaping regulations. In all, he has sent 285 oversight letters to government officials since January 2015, McIlheran said.

Johnson is getting involved just as electronic nicotine delivery systems — e-cigs, vape pens and other products — are exploding in popularity. The FDA announced last month that it would take steps to restrict youth access to e-cigarettes and extend certain traditional tobacco rules to nicotine-containing vaping products.

The science on the health effects of e-cigarettes has stirred political debate.

Last year, a Journal Sentinel investigation, "Gasping for Action," found high levels of harmful chemicals in locally made e-liquids. It also exposed inadequate testing that allowed manufacturers to make false claims that their products were free of these lung-destroying chemicals, such as diacetyl. A Harvard University study found similar results late last year.

But McKenna and Johnson are both relying on the work of a controversial scientist to fight efforts to regulate the vaping industry.

Johnson's staff said The Wall Street Journal opinion piece on vaping that caught the senator's attention was by Michael B. Siegel of the Boston University School of Public Health and head of the nonprofit Center for Public Accountability in Tobacco Control.

McKenna offered to provide contact information for Siegel to combat "the appalling disinformation peddled about" e-cigs.

Siegel has been accused of blowing smoke by some critics with his research disputing that transient exposure to secondhand smoke increases heart attack risk in individuals without coronary disease. He is a foe of outdoor smoking bans and has taken on such anti-smoking groups as the Campaign for Tobacco-Free Kids.

"I view him as a tragic figure — he has completely lost it," University of California tobacco researcher Stanton Glantztold The Boston Globe in 2007. "His view is that everybody in the tobacco control movement is corrupt and misguided except for him."

It's not surprising that Johnson has taken a keen interest in McKenna's pet cause.

McKenna did an online ad for an e-cigarette company years ago. She testified at a state Senate hearing in 2014 in support of a bill allowing people to use vaping products indoors.

"I found out that, over the course of a few days, I was able to transfer my dependency of cigarettes to the use of an e-cigarette with substantial benefits to my health," McKenna said.

McIlheran said there's a good explanation for the large number of appearances Johnson has made on McKenna's show. The senator made more than 400 pre-booked radio and TV interviews in Wisconsin and nearby states in the past year — many on conservative talk shows that support Republican candidates and causes.

"Her distinct Madison and Milwaukee shows serve largely nonoverlapping audiences, so often an appearance on one can repeat topics from the other," McIlheran said.

On air, McKenna and Johnson talk about much more than just politics. They've chatted about his emails in the "wee hours," his mother calling him "Ronnie," their trip to a McFarland bar to watch a Badgers game, their mutual fondness for SweeTarts candy and his no-shave November beard.

Both insisted their opposition to FDA regulations of e-cigs is not a coordinated campaign.

It's more like a shared interest — one of many.

"He is ... the chair of the committee that oversees government in the U.S. Senate, so I'm happy to have him on my program any time," McKenna said of Johnson.

Contact Daniel Bice at (414) 224-2135 or dbice@jrn.com. Follow him on Twitter @DanielBice or on Facebook at fb.me/daniel.bice.