The Message Machine: Colorado edition

We've been fact-checking political campaign ads in partnership with NPR. In our latest installment, we looked at ads from the Republican primary in the U.S. Senate race in Colorado. The candidates are Jane Norton, a former lieutenant governor who got early backing from Republican Party leaders, and Ken Buck, a district attorney who has received backing from the tea party movement.

Here's what two bare-knuckled ads had to say:

"Our country is at the brink," a narrator says in an ad from Americans for Job Security. "Colorado families and workers need relief -- yet Jane Norton supported the largest tax hike in Colorado history, costing us billions. And Jane Norton's record on government spending? The state bureaucracy she managed grew by $43 million in just three years. Record taxes and reckless spending has cost Colorado jobs. Call Jane Norton, tell her no more tax hikes and big government spending."

Norton shot back with this:

"Seen those TV ads attacking me? They're paid for by a shady interest group doing the bidding of Ken Buck. You'd think Ken would be man enough to do it himself," Norton says in her own ad.

"Here's the truth: In state government, I cut budgets, cut programs and reduced staff," Norton continues. "Ken Buck's Office? His spending skyrocketed by 40 percent. We need a senator who's actually cut spending and has the backbone to stand her ground."

We looked at whether Norton "supported the largest tax hike in Colorado history" and if  "the state bureaucracy she managed grew by $43 million in just three years." We rated both statements Half True.

We also looked at whether spending at Buck's office "skyrocketed by 40 percent." We rated that Mostly True.

Be sure to click the links to read our reasoning and for complete source lists.