Sen. Time Kaine (D-VA) is considered to be an odds on favorite to be Hillary Clinton’s choice for Vice President at the DNC convention this July in Philadelphia.

Which makes this exchange on NBC News’ Meet the Press so curious. Host Chuck Todd asked Kaine if he was “qualified to be commander-in-chief.” Kaine’s response:

https://www.youtube.com/watch?v=LuFBcEXrGLg

“You know what? Nobody should ever say they’re ready for the responsibility because it is so, so huge.  Abraham Lincoln wouldn’t have said yes to that question. Harry Truman wouldn’t have said yes to that question. Those are are my two favorite presidents. I am doing my best to be a good senator.”

A humble and sober response to a question that, truly, hardly anyone can ever actually respond to without some level criticism.

However, what makes Kaine’s answer so curious is that it completely undermines one of Hillary Clinton’s strongest arguments for her candidacy: That she is so experienced that she will be ready from day one. No on-the-job training for Hillary. She’s been in the inner circle of presidential power for decades,. No one is more prepared for the presidency. She and her supporters claim.

Bernie’s attack on @HillaryClinton tonight was beneath him. She is the most qualified person to ever run for POTUS. https://t.co/v4oLrxenXx

— Barbara Boxer (@BarbaraBoxer) April 7, 2016

A recent fund-raising email from her campaign featured her campaign manager, Robby Mook, asked supporters to “show how proud you are to support the most qualified candidate in the history of our country.”

So if she is the most qualified person to ever run for president, and she is “ready from day one” to be commander-in-chief, how does that reconcile with her potential running mate claiming “nobody should ever say they are ready to be president?”

This kind of misstep, coupled with a growing concern among Democrats that in a campaign season that features the aggressive tactics of Donald Trump, Kaine is too “mild mannered” to do an effective job as Clinton’s “attack dog” in 2016 may suggest that Kaine isn’t actually a safe bet for the VP slot.