Youth torments liberal sage: A brash Republican may topple the staid Democratic incumbent, writes Rupert Cornwell in Philadelphia

ANOTHER barb flies from his youthful tormentor and Harris Wofford looks less angry than deeply, deeply pained. 'That is simply not correct,' he sighs, wagging a professorial finger in the direction of Rick Santorum, who has just produced an especially blatant distortion of his Democratic opponent's position on defence.

The exchange was just one of half a dozen like it as the 1994 Pennsylvania Senate race moved this weekend to the debating studios of a Philadelphia television station. Conceivably, President Bill Clinton's tenuous control of Congress could hinge upon its outcome; but that is not why the contest is being so closely followed. Of the 35 Senate seats at stake this autumn, none offers so perfect a contrast of style, age and ideology. Mr Wofford against Mr Santorum is the old against the new. And, right now, the tide is running in favour of brash and eager youth.

How much can change in three years. In 1991, Mr Wofford won an astonishing victory in the Senate by-election, erasing a 40-point lead of ex- attorney-general and former Pennsylvania governor Dick Thornburgh, and pointing the way to Mr Clinton's national triumph a year later. It was built on two things: Mr Thornburgh's fatal complacency, later mirrored by George Bush, and a humdinger of a campaign line.

Mr Wofford become the first candidate to turn health care into an issue that could swing elections. Such was his celebrity that he was on the four-man Clinton short-list for vice-president. But today health reform - at least of the type Mr Wofford advocated - is dead, its corpse brandished by Republicans as another trophy in the battle against liberalism and Democratic 'Big Government'.

Not surprisingly, he is on the defensive, harried from pillar to post across the state by an opponent half his age, an old liberal stag under chase for perhaps the last time. At 68, Mr Wofford is a courtly figure, an adviser to John Kennedy and Martin Luther King, civil-rights activist and a founder of the Peace Corps, decent and dignified as a US Senator was supposed to be.

In any 'normal' year, Mr Wofford's credentials and prestige would have made him a reasonably safe bet. But with barely three weeks to go, Mr Santorum has caught up - and may be a whisker in front. Steadily, Pennsylvania edges up the list of seats the Republicans expect to win in 1994, in their drive to seize control of the Senate for the first time in a decade.

Some of Mr Wofford's problems are far beyond being solved by him.

Pennsylvania, which before him had not sent a Democrat to the Senate since 1962, cannot escape the national shift toward the Republicans. In an autumn filled with grim tidings, nothing has scared Democrats as much as a survey last week showing that even the so- called 'generic vote' has tipped against them. When asked who they would prefer to represent them in Congress, people picked Republicans by a 47 to 44 majority. Even in Ronald Reagan's heyday, that never happened.

Pennsylvania too shares the foul, almost irrational, anti- Washington mood rife across the country. In 1991, Mr Wofford was the outsider: now he is just another reviled incumbent. He must, moreover, carry the cross of loyalty to his leader in a state where the President's approval rating is barely 30 per cent. 'A mouthpiece, an absolute lapdog of Bill Clinton,' sneered Mr Santorum this weekend. The wince from Mr Wofford was almost audible.

But even if times were normal, Mr Santorum would be a formidable opponent.

In Pennsylvania, Republican senators have tended to be moderate. He, though, is a sabre-toothed conservative, protege and ideological soulmate of Newt Gingrich, the fiercely partisan Republican House Whip who could be the next Speaker. Now 36, Mr Santorum entered Congress in 1990, when by dint of sheer shoe-leather he won a blue- collar, solidly Democratic district in Pittsburgh.

On Capitol Hill, he quickly emerged as one of the 'Gang of Seven' Republican newcomers who helped expose the scandals at the House Bank and Post Office.

With his cropped hair and slightly protruding ears, he brings to mind a younger version of Prince Charles. But Mr Santorum has a model family and betrays not an iota of self- doubt. Mr Wofford's scoldings of him as a hypocrite, calling for change while being an unabashed agent of Congressional gridlock, bounce off him like paper darts off a battleship.

Maybe, an old-fashioned politician - with the very modern assistance of dollars 1.3m ( pounds 820,000) thus far of negative advertising and the consulting skills of Messrs James Carville and Paul Begala of Little Rock 1992 fame - will yet prevail. For all his political skills, Mr Santorum's raw conservatism could yet be too much for staid old Pennsylvania. If so, the Republicans may just fail to seize the Senate. But in both cases, don't bank on it.

Would-be president, page 19