HOUSTON -- Only a few weeks ago, Republican George Bush, the son of the former president, appeared poised to take command of the Texas governor's race with a blistering attack against incumbent Ann Richards' record on crime, welfare, education and state spending.


But now, it is Bush, 48, a businessman who has never held public office, who finds himself dodging flak. In biting television ads and a grueling schedule of appearances, Richards appears to have regained the initiative with a lacerating counterattack that portrays Bush as unqualified, unethical and a failure in business who has floated through life on his father's name.


"What you have here is a Johnny-come-lately who has spent his whole life eating off a silver platter, and we are not going to let him lead our state," said Richards, 61, at a rally in Houston.


In the closely watched Massachusetts Senate race, there has been a similar reversal of roles. After months on the defensive, Democratic Senator Edward Kennedy has used a volley of harsh negative advertisements to reopen a gaping lead over Mitt Romney, another first-time candidate whose youth and slim good looks seem almost to mock Kennedy's mottled and bloated visage.


Likewise in Florida, Democratic Governor Lawton Chiles, 64 -- who two weeks ago looked like a retirement waiting to happen -- has fought back to at least a dead heat with an uncharacteristically personal counterattack against Jeb Bush, more than two decades Chiles' junior and another son of the former president.


This pivot between hunter and prey is apparent in more than half a dozen Senate and gubernatorial races where a Democratic incumbent faces serious challenge.


Struggling against opponents who are either much younger, or are new to politics, veteran Democrats from Richards, Chiles and Kennedy to governors Mario Cuomo of New York and Zell Miller of Georgia and Senators Dianne Feinstein of California and Jim Sasser of Tennessee have fought their way off the mat with remarkably similar strategies.


Partly they are emphasizing their experience and accomplishments; but mostly they are ferociously attempting to redefine their opponents as unknown and untested quantities with slippery ethics and hidden agendas.


In effect, these Democrats are trying to convert the principal asset of their opponents -- their freshness -- into a source of suspicion. On the unlined faces of their youthful challengers, these battle-scarred Democrats are trying to tattoo words like rich dilettante, tax dodger, business failure, and savings-and-loan cheat.


Their cause has also been helped by a series of desertions by high-profile Republicans who crossed party lines to back Democratic candidates.


In recent weeks, New York City Mayor Rudolph Giuliani has backed Cuomo; Los Angeles Mayor Richard Riordan has endorsed Feinstein; Nancy Reagan joined a parade of Republicans who have criticized Republican Senate candidate Oliver North, while Ross Perot publicly threw his support behind Richards on Tuesday.


But to suggest that these new trends will help Democrats to turn the tide of popular feeling would be premature and probably overly optimistic: In the end, despite President Bill Clinton's recent gains in the polls, the anti-Democratic currents coursing through parts of the nation may still sweep away several key Democrats.