The Mitt Romney campaign is making a multi-million broadcast TV ad buy Pennsylvania in an attempt to snuff out Rick Santorum's presidential challenge for good, reports PoliticsPA. The spots start Monday everywhere but Pittsburgh, then come into Santorum's former home town in the week leading up to the April 24 primary.

His SuperPAC is already on cable (ie, Fox News). The campaign's more-expensive broadcast TV buy includes almost 6,000 gross ratings points in the Erie market, nearly 5,000 around Johnstown and more than 3,000 around Philadelphia.

From PP's Keegan Gibson:

Chris Nicholas is a GOP campaign veteran who has bought statewide TV time in multiple states over the past decade, including Pennsylvania. He said the buy is enormous.

“This is an incredible amount of points in two weeks,” he said. “I’ve never bought more than 1,500 a week.”

Industry shorthand suggests that for every 100 GRP, the average viewer sees an ad once. That means the average Erie resident will see a Romney ad 59 times in the next two weeks.

Finally, the road to the White House passes through Harrisburg. A few images from the GOP campaign trail this week -- at least the portion that went within a few miles of the Capitol newsroom.

On a rooftop in downtown Harrisburg:

And at a Mechanicsburg bowling alley:

Photos: Langley iPhone

Rick Santorum's 3-year-old daughter, Isabella, who suffers from the genetic disorder, trisomy 18, is being hospitalized. The campaign released the following statement:

Hogan Gidley, National Communications Director, said: "Rick and his wife Karen have taken their daughter Bella to the hospital. The family requests prayers and privacy as Bella works her way to recovery."

The campaign released no other details. Mr. Santorum briefly interrupted his campaigning in January when Bella was hospitalized for pneumonia. There was no other word on his daughter's condition or how it might affect his campaign schedule. He had no events planned in the next few days due to the Easter holiday.

Mitt Romney, said, in a message posted on Twitter, "Praying for a quick recovery for Bella. Ann and are keeping Rick, Karen, and the entire Santorum family in our thoughts.''

There was a promise of no more Daily Santorum updates this week, but just a couple links anyway for the guy who's staring down the second-worst bout of publicity in the nation this week (Pitt doesn't seem so bad now, does it Jeff Long?)

Jim O'Toole has the poll roundup and Laura Olson has the first (of many we imagine) Romney natural gas/fracking pressers.

After you finish Robert Costa's look at the Pa landscape here's a valedictory from Walter Shapiro at the New Republic:

More than any presidential candidate since maybe Gary Hart in 1984, Santorum vindicated the quixotic dreamers who struggle on despite invisible poll ratings, tin-cup financing, and the dismissive wisecracks from political insiders. Santorum was a throw-back candidate—not only with his 1950s social values, but also in his forged-by-necessity embrace of the most old-fashioned way of running for president. In Iowa, where he made his move in the polls only two weeks before the January 3 caucuses, Santorum campaigned everywhere, responded at (sometimes tedious) length to every voter question, and cheerfully deflected skeptical press queries like the one I posed to him in mid-December: “Some days, don’t you get discouraged?”

Romney will reach into his deep wallet and start the Pa air war Monday (Politico)

On the other hand, Santorum's SuperPAC is staying out of the state so far (The Hill)

Brutal lede from Marc Levy ("kicked" "sour" "fading") at the AP.