Michelle Fields has conducted herself admirably since Donald Trump campaign manager Corey Lewandowski grabbed her by the arm after a news conference last month, but the former Breitbart News reporter veered off the high road Wednesday night when she took a swipe at Fox News Channel host Greta Van Susteren.

Fields told the Blaze, Glenn Beck's news site, earlier in the evening that she planned to sue Trump and Lewandowski for defamation because they originally denied the grabbing incident happened and portrayed her as a serial liar. Surveillance footage obtained by police proved that Lewandowski did, in fact, grab Fields by the arm, prompting a misdemeanor battery charge against the campaign manager. But Politico reported Wednesday that Palm Beach County (Fla.) State Attorney David Aronberg would not prosecute the case.

Van Susteren, a former trial attorney, reacted to the news by recommending that Fields abandon the idea of a civil suit.

"She is just not going to win, and it will be expensive and a heartache," Van Susteren wrote. "Just so we are clear," she added, "I am not 'for' assault. I know the court system."

Fields didn't seem to appreciate the advice.

Fields is obviously free to pursue whatever course of action she thinks best. But Van Susteren, whose legal background informs her news analysis, was just doing her job. Her belief that Fields would probably lose a civil case carries some weight.

What's really at stake here, however, is Fields's status as the bigger person in her dispute with Lewandowski. Even if the criminal case does not move forward, she can emerge as the winner. Trump and his campaign manager denied there was any contact — Lewandowski even called Fields "delusional" — but video evidence backed her up. They tried to smear her reputation; she refrained from personal attacks. Fields has kept her composure and earned respect in the process.

But if she gets sucked into petty name-calling, Fields risks looking like the campaign that wronged her. An episode that has resembled a strong-willed underdog standing up to a bully could morph into an ugly row between equally crude combatants.

I doubt that's what she wants.