New York (CBS)  -- DEMOCRATS FACE KEY TEST IN KEYSTONE STATE

Hillary Clinton is ahead in the polls in tomorrow's Pennsylvania Primary, but she needs to win convincingly.  Barack Obama can afford to lose in Pennsylvania, as long as he doesn't lose by too much. 

It will take a day or two, maybe a week or two, to play out, says CBS News Senior Political Correspondent Jeff Greenfield.  The superdelegates, who hold the balance of power at the Democratic Convention, are watching Pennsylvania closely.  They know that the Keystone State could be key to the White House in November.

"The Clinton people are saying, 'Look, Obama's weak where Democrats have to win.'  And the Obama people say, 'Look, any Democrat wins New York and California -- we're strong in competitive states and even red states, like Virginia.'  So what happens in Pennsylvania will tell you whether Clinton's or Obama's argument gains strength in the next couple of weeks," said Greenfield.

What Hillary Clinton is saying to Pennsylvanians is this.

"I believe I have a unique set of experiences and qualifications to ready on day one to be the Commander-in-Chief, to end the war in Iraq, to bring our troops home," said Clinton.

And Barack Obama is in the attack mode.

"You can't be for the war when it's popular.  And then, when you find out it's unpopular, you say, 'Well, I wasn't voting for the war -- I was voting for diplomacy,'" said Obama.

In other words, says Obama.

"She's embraced the strategy of Washington, which is say anything and do anything," said Obama.

It's clear that Democrats want to run against George Bush. Obama, damning with faint praise, said all three of the candidates -- he, Clinton or John McCain -- would be better than Bush.

"Senator Clinton will be vastly better than George Bush would be.  But that's a very low bar -- that's not good enough," said Obama.

Says Clinton: "We need a nominee who will take on John McCain, not cheer on John McCain -- and I will be that nominee."

THE LATEST CRYSTAL BALL ON THE ECONOMY

Harry Truman once said he wished he could find a one-handed economist because every time he went to an economist for guidance.  He was always told:  "On the one hand, this. On the other hand, that."

The National Association for Business Economics, the NABE, has just put out the results of a poll of 109 economists as to how the U.S. economy will do.  If you think consulting one economist is frustrating, think how many other hands you get with 109.  

The 109 economists consulted by the National Association for Business Economics all work for NABE member companies. 

Of these 109, only 30% said they believe the economy will shrink in the first half of this year.  But the lead of the story as it appears on the wire services is: "The odds the United States will fall into its first recession since 2001 are rising sharply."   

How do they arrive at that?  Well, in January it seems only ten percent of them thought the economy would shrink, so three times as many think so now.  And even the ones who are not ready to pronounce us in a recession don't think the economy will do as well as they thought three months ago.

"Seventy percent said that they've tuned down their outlook for 2008," said Ken Simonson, the point man for the NABE's survey of economists. Mr. Simonson happens to be an economist himself, the chief economist for the Associated General Contractors of America.

"In the construction industry, we've seen a huge acceleration just recently in the cost of diesel fuel and in steel," said Simonson.

Everywhere you look, he says, "More commodities cost more. Imported goods cost a lot more."

So for him and his business.

"I think the biggest problem is higher materials costs," said Simonson.

The U.S. economy grew at a pace of only 0.6% in the last quarter of last year. The government won't report on the second quarter results until July.  If you can't wait 'til then, ask an economist, preferably a one-handed economist.

A RUSH FOR NATURAL GAS

There's a layer of rock with natural gas in it called the Marcellus Shale -- running 7,000 thousand feet deep along the Appalachian basin from New York through Pennsylvania down into West Virginia. And energy companies have been paying farmers top dollar lately for the rights to drill for it.

"It's like a gold rush of sorts. In the last two years, prices on a per acre basis went from $15 an acre to $300 an acre -- and within about the past two months, they've gone from $300 to now over $2,000 closer to $2,500," said Tom Murphy, an educator at Penn State Cooperative Extension.

For a Pennsylvania landowner like Elizabeth Downey, the idea of drilling for natural gas under her land bothered her a bit.

"We worked so hard for this place. I don't want to do anything to jeopardize it," said Downey.

But how could she refuse?

"We were offered $1,500 an acre by one company and we accepted that and it means that initially we'll see around 153, 155 thousand," said Downey.

Farmer Allen Williams plans to sign over more than 500 acres.

"It's probably over a million dollars. And that, for me in my lifetime is certainly different than what I'm used to," said Williams.

Energy companies are taking a gamble.

"We believe the Marcellus shale holds many million cubic feet of natural gas," said Mike Hallford of Chief Oil and Gas. "We're somewhat of risk takers, gamblers. We could be in the billion range, as to what we going to make."

At Penn State's cooperative extension, Tom Murphy has been holding seminars to help the landowners to protect their rights.

"I'm not sure that everyone here understands is how many wells could be here in the future," said Murphy.

FEDS PLAN DNA DATABASE FROM EVERY PERSON THEY ARREST

The Federal Government plans to start taking DNA samples of anyone arrested by a federal law enforcement agency, and from foreigners who are detained, whether they've been charged with any thing illegal or not. 

The DNA will be collected through a cheek swab. Until now, this would only be done with convicted felons.  But under the new plan, the Justice Department estimates that 1.2 million DNA samples would be added to their database, known as CODIS, each year. 

Some people think it's an invasion of privacy. But a Chicago study done in 2005 found that 53 murders and rapes could have been prevented, if a DNA sample had been collected on arrest. 

There are civil liberties questions that rise from taking and keeping somebody's DNA. Among them the potential for misuse of such personal information, as family ties and genetic conditions. 

The Justice Department says none of the DNA samples collected will be used for identifying genetic traits, diseases or disorders.  Nor would the rules allow for DNA samples to be collected from immigrants who are legally in the United States, or being processed for admission, unless that person was arrested. Then they'd be like anybody else. 

The proposed rule is being published in the Federal Register and that will be followed by a 30-day period for public comment.  There are similar laws in 13 states already. The authorization for the Federal Government to expand DNA sampling comes from two separate laws Congress passed in 2005 and 2006.

It's only been technologically possible to collect and store DNA since the 1990's. If they'd started doing it then, says the Chicago study, many innocent lives could have been saved. If a person is arrested but not convicted, the Justice Department says he or she can ask the Department to destroy the sample.