Politicians like talking about 'evidence based' decisions. But whose evidence?

When something is 'evidence based,' it sounds like a fact. That makes the term a useful tool for politicians. It's a staple for Hillary Clinton, in particular.

“Evidence based.” Relying on scientific or other research data, as opposed to just political beliefs.

Politicians like the use the word “evidence” – which evokes the image of accusatory material that prosecutors introduce in courtroom trials – to make their views sound fact-based and rational, whatever the truth might be.

Consider Texas Sen. Ted Cruz’s crusade against “global warming alarmists” who, in the view of the 2016 Republican presidential candidate, are misguided on science. “Anyone who actually points to the evidence that disproves their apocalyptical claims, they don’t engage in reasoned debate. What do they do? They scream, ‘You're a denier.’ ” Senator Cruz told The Texas Tribune in March 2015.

Another Texas Republican, state Land Commissioner George P. Bush, recently pushed back against a Houston Chronicle story showing that he’s been out of the state or off work nearly half of the time since his father, Jeb Bush, became a presidential candidate. “The evidence will strongly show that I've put my heart and soul into this position,” the younger Bush said.

Across the ideological spectrum, “evidence based” has become a favorite term of Hillary Clinton’s. Her campaign site touts a school-based approach to battling alcohol and drug addiction: “Clinton will help state and local leaders put in place effective, evidence-based, and locally-tailored programs to meet their needs.”

That’s an extension of Mrs. Clinton’s more partisan evidence-based comments leading up to her second White House bid. She has used it to contrast what she regards as the knee-jerk political posturing of Republicans.

“I want to get back to evidence-based decision-making.… There’s too much that has gone on in our politics recently that is just pure ideology, pure partisanship,” she said at an April 2014 conference. Five months later, as she inched closer to becoming a formal candidate, she called for “evidence-based optimism.”

And after actually becoming a candidate in March, she expressed relief at a conference on urban development at not having to address nagging questions about her e-mail server when she was secretary of State: “I love sessions like this, because it’s really nice to get back into an evidence-based discussion.”

But there’s evidence that “evidence-based” actually can be bipartisan.

In one of the rare collaborations in Congress between a senior Republican and a senior Democrat, Wisconsin GOP Rep. Paul Ryan and Washington Sen. Patty Murray introduced a bill earlier this year to create an “Evidence-Based Policy Commission.” It called for setting up a 15-member commission of experts in data and statistics to see whether a central data clearinghouse would help with making spending decisions without violating privacy rights.

Chuck McCutcheon and David Mark write their "Speaking Politics" blog exclusively for Politics Voices.