What is it about Republican...

...presidential candidates who travel to London?  First it was Mitt Romney, who:

...in an NBC interview in July 2012, described reports of security problems with the summer games in London as “disconcerting,” and said, “It’s hard to know just how well it will turn out.” The comments from the former Massachusetts governor, who chaired the winter Olympics in Salt Lake City in 2002, overshadowed meetings with top political leaders including [Prime Minister David] Cameron.

This week it was Chris Christie:

After President Obama urged people to get vaccinated amid a measles outbreak, reporters asked Christie about his views on the matter. “Not every vaccine is created equal, and not every disease type is as great a public-health threat as others,” he said.

The New Jersey governor had to walk this back as well as his comment that:

...parents need “some measure of choice” on childhood immunizations.

Next it's Gov. Scott Walker, who's heading to London later this month.

So what is it about Republican presidential candidates and London? Is it the jet lag? Or are they just not used to talking to reporters who don't work for Rupert Murdoch?*

* By the way, Walker ventured outside the Fox "News" bubble on Sunday (my emphasis):

On ABC's "This Week," Walker was asked by Martha Raddatz about foreign policy, specifically Syria. He charged that the U.S. was insufficiently aggressive against Islamic State. In Syria, he said, "we have to be prepared to put boots on the ground." 

D'oh!