From a (Harrisburg, PA) Patriot-News profile of Chris Matthews packed with will-he-or-won’t-he-run-for-Senate speculation:

A Senate run would demand discipline, said Chris Borick, a political analyst at Muhlenberg College.

“It would be interesting to see if he could control himself under the spotlight of a senatorial campaign,” Borick said.

At times, he can show great restraint. When syndicated columnist Robert Novak struck a pedestrian with his car last week, Matthews resisted his initial thoughts of having fun with the story and played it straight.

Just like Stephen Colbert on last night’s The Colbert Report, when after reporting that Novak had been hospitalized for a brain tumor Colbert surprised himself by abruptly tabling a planned segment on all the recent Robert Novak news (“I’m not doing something I’d planned on doing just because of how it might affect someone else. I’m pretty impressed with myself right now.”) Within minutes Colbert was promoting his upcoming “Special Report,” “Silent Night: Stephen Colbert’s Heroic Refusal To Discuss Robert Novak.”

More from that Patriot-News profile: “one person familiar with Matthews’ deliberations” actually points to Matthews’ recent appearance on The Colbert Report (during which Matthews told Colbert he’s wanted to “be a senator” since he was a kid and Colbert announced, “That’s an announcement!”) as having “hit a nerve” and, according to this “one person,” made Matthews “focus” on the idea of a senate run “and think, ‘That would be really interesting.’”