Rick Santorum was supposed to be back to campaigning today, but, with Bella still in the hospital, he’s extended his pause in activity. Out of deference for that decision, the Mitt Romney campaign indefinitely pulled a snarky spot that was supposed to air in Pennsylvania.

“We have done this out of deference to Sen. Santorum’s decision to suspend his campaign for personal family reasons,” Romney spokeswomanAndrea Saul said in an email.

Mr. Santorum’s three-year-old daughter Bella, who has a genetic condition, was hospitalized Friday.

The negative spot has been pulled until further notice, Romney aides said Monday morning. Mr. Santorum’s campaign has said the candidate plans to return to the campaign trail Tuesday.

The ad, which was scheduled as part of Romney’s reported $2.9 million ad buy in the Keystone State, posed this zinger to Pennsylvanian voters, who rejected Santorum’s 2006 bid for the U.S. Senate by 17 points: “We fired him as senator. Why promote him to president?” The Romney campaign now plans to run a positive ad that focuses on the former Massachusetts governor’s record instead.

It might not seem like much, but the decision is probably both a sign that Romney feels increasingly confident and secure in his status as the likely nominee and a sign that he genuinely respects Rick Santorum, who has proved himself not only a worthy competitor but a man of character. (Could it be that it counted with Romney that Santorum never stooped so low as to attack Romney’s time at Bain Capital, never fueled the conservative opposition with misplaced attacks?) Romney wants to sew up the nomination as quickly as possible — but he’s unwilling to do it at the expense of the personal peace of a man of integrity like Rick Santorum. It should be encouraging to conservatives across the country that these men are the finalists for our nomination. As evidenced by their commitment to their own families, they both understand “the permanent things.”

In good news, though, the Santorums have announced that Bella could be out of the hospital as soon as today. Santorum says he plans to return to the campaign trail tomorrow.