President Trump ridiculed Sen. “Air Claire” McCaskill (D-MO) in a tweet Wednesday, calling her “so phony” because she “flew around in a luxurious private jet during her RV tour of the state.”

Trump also endorsed her leading opponent, Missouri Attorney General Josh Hawley, for the U.S. Senate election in November. Hawley faces minor opposition in the August GOP primary.

Senator Claire McCaskill of the GREAT State of Missouri flew around in a luxurious private jet during her RV tour of the state. RV’s are not for her. People are really upset, so phony! Josh Hawley should win big, and has my full endorsement. — Donald J. Trump (@realDonaldTrump) June 13, 2018

McCaskill’s defense of her use of an airplane on the RV Tour amounted to this: it wasn’t a fake RV tour, it was only partially fake.

“Paying on my own dime to visit more Missouri veterans is not something I’m going to apologize for,” McCaskill said in a statement, as reported by ABC News on Thursday.

Her campaign, however, admitted that the “RV Tour” of the state, which began on May 30 and ended on June 1, was not a real “tour” in the way most Missouri voters who travel by RV consider a tour.

“Claire spent two days traveling the state on the RV and only flew to where she stayed overnight and to allow for an additional stop that otherwise would not have been possible,” McCaskill campaign spokesperson Meira Bernstein said in a statement released to ABC News.

The issue, however, is not really whether McCaskill paid for her own travel on the RV Tour, but if she misled Missouri voters to believe that she was on the RV all the time during the tour.

“McCaskill’s private plane usage became an issue in 2011 when the public learned she had not paid hundreds of thousands of dollars in property taxes on a plane she sold in 2011,” Breitbart News reported on Wednesday:

The RV tour, which concluded on June 1, was advertised as just that. The impression given was that McCaskill was just like any other Middle American who hits the road on camping trips. She’s just like us! is how the trip was presented, and at no time was the public informed McCaskill was flying on a luxury plane when voters were led to believe she was riding in a luxury RV.

According to the most current Real Clear Politics Average of Polls, McCaskill maintains just a 1.7 percent lead over Hawley in the November general election, which is within the margin of error.

Hawley’s prospects brightened considerably earlier this month when embattled Missouri Gov. Eric Greitens, a Republican, resigned rather than face likely impeachment proceedings in the State Legislature arising from a burgeoning scandal related to an extramarital affair.

As Attorney General, Hawley had become entangled in the mess when he filed a lawsuit against Greitens. With Greitens now out of the picture, Republicans in the state have plenty of time to unify around Hawley, who faces only minimal opposition in the August primary.

Missouri Rising Action was quick to take advantage of McCaskill’s latest air travel problem, launching this digital ad on Friday attacking her as “Rich and Liberal.”

You can read the full transcript of the ad here:

It’s lifestyles of the rich and liberal… …the untold story of millionaire Claire McCaskill. While Missouri families struggle, Claire McCaskill is living large… Fleecing taxpayers for over seventy grand in flights on her private plane… Taking the elevator instead of the stairs in her seven thousand square foot mansion… And investing a hundred grand in rare Chinese art and antiquities… …all while looking down on Missourians from her two point seven million dollar luxury condo in DC. McCaskill laughs all the way to the bank…pocketing over twenty million bucks in corporate welfare while hardworking taxpayers foot the bill. An elitist liberal, Claire McCaskill votes with radical Massachusetts Senator Elizabeth Warren eighty eight percent of the time… …while cutting thousands in checks to Hillary Clinton. Millionaire Claire McCaskill. She’s rich. She’s liberal. She’s out for herself.

McCaskill has been rated as one of the most vulnerable senators up for re-election in 2018.

She is one of ten Democratic incumbents running for re-election in 2018 in a state Donald Trump won in 2016. In addition, a recent Morning Consult/Politico poll shows that she has a negative net approval rating, with only 39 percent of Missouri voters giving her a positive approval rating and 44 percent giving her a negative approval rating.