In his march toward the GOP presidential nomination, Mitt Romney was going to use his latest television commercial to remind Pennsylvanians of 2006, the year that Rick Santorum lost his seat in the Senate. It was a stunning upset: a double-digit loss across all major racial, income, and age demographics.

The spot, which was slated to run in Pennsylvania this week before the state’s primary later this month, is undoubtedly ruthless. “Rick Santorum 17-point loss, historically embarrassing,” the voiceover bellows between news clips of news anchors explaining just how badly Santorum was beaten. Then the kicker. “We fired him as senator, why promote him to president?”

Ouch.

The ad is accurate. There are no stretches of the truth. Santorum lost badly, end of story. Yet its vigor brings on a more existential campaign question: is it possible a campaign ad can be too merciless. Even cruel?

If it is, then this ad does it. Not entirely because of the ad, which is by now normal during a campaign season marked by Republicans shredding each other about their professional and personal records. In late January, Romney used the same method—letting unfavorable news coverage of his competitors speak for itself—to slam Newt Gingrich’s departure as speaker of the House.

But sometimes in campaigns, context matters. Timing does, too. And this week turned out to be a poor week to be callous toward Santorum.

Santorum’s 3-year-old daughter, Bella, was hospitalized last week with complications from a rare genetic condition called trisomy 18. The disorder is caused by an abnormal chromosome count and usually brings heart defects, kidney problems, and developmental disabilities. Bella isn’t always present on the campaign trail, but she symbolizes Santorum’s views about parenting and abortion—he often talks about her in stump speeches, making her familiar to supporters.

So on Monday morning, right when the ad was supposed to run, Romney’s campaign pulled it from Pennsylvania stations. A Romney spokesman said that the campaign wanted to be sensitive during a tough time for the Santorum family and asked that a pro-Romney ad run in its place.

Santorum’s campaign says that the senator is expected to be back campaigning on Tuesday, desperate to stay competitive before the next round of primaries. Some Republican pundits have speculated that a loss in Pennsylvania could be too embarrassing for Santorum to overcome, signaling the end of his campaign.

Romney’s ad, still, is a fair one, pointing out the weaknesses of Santorum’s candidacy in his home state (even his home county, which he lost by 30 points). But with all the sympathetic press being poured on Santorum’s ill daughter, it just wasn’t the best time for Romney to hit him that hard.