Theory: If you’re a candidate, and your surrogates have to tell voters not to do what they’re emotionally inclined to do, you’re in trouble.

Example:

Former President Bill Clinton, who remains deeply popular in this steel-and-coal district, capped off an afternoon rally at the Frank J. Pasquerilla Convention Center where he touted Democrat Mark Critz as the logical heir to the Murtha legacy . . . The former president alluded to the electorate’s angry mood. “Think about decisions you made when you were really mad,” Mr. Clinton told the audience. “It’s about an 80 percent chance you made a mistake.”

Indeed, Mr. President,  I can think of a lot of folks who were mad at George H. W. Bush over breaking his “read my lips, no new taxes” pledge, and so they voted third-party or stayed home, and you know how that story turned out.

Meanwhile, Republican Tim Burns’s campaign noticed that all of the security costs for Clinton’s visit were covered by Johnstown, Pa., and not the Critz campaign. I guess that approach is fiscally conservative . . . for him.