Washington ? The 2004 presidential election gives Americans the most dramatic choice of leaders and directions in at least a quarter of a century.

So different are President Bush and Massachusetts Sen. John Kerry — in everything from personal style to their approaches to major international, domestic and cultural issues facing the country — that voters have, in effect, a choice between ratifying America’s current path and charting a new one.

Like other historic elections, in 1980, 1964 and 1932, the outcome of this year’s vote could usher in a radically different way of governing. It’s worth noting that the three earlier elections produced landslides. But whoever wins, and by whatever margin, the outcome will have important consequences for Americans’ prosperity and safety and for their country’s role in the world.

“The difference couldn’t be more stark,” said Susan Dunn, a presidential historian and co-author of a new book on George Washington.

Bush, 57, is a plainspoken, backslapping, peanut-butter-and-jelly loving Texan who enjoys watching baseball but prefers the solitude of running for his exercise. He launched a pre-emptive war in Iraq, favors suspending some legal rights for suspected terrorists, presided over soaring federal budget deficits, wants to extend tax cuts, backs free trade as an engine of growth regardless of short-term job losses, wants to partly privatize Social Security and wants a constitutional ban on marriage for gays and lesbians.

Kerry, 60, is sometimes aloof and long-winded, patrician, a French chocolate-eating New Englander who unwinds with the team sport of ice hockey. A Yale University graduate like Bush, Kerry served in combat in Vietnam while Bush served at home in the Texas Air National Guard. Kerry, a liberal, now criticizes the Iraq war he voted to authorize. He’d raise taxes on those who make more than $200,000 a year, expand health care to the uninsured, restrict trade to protect jobs regardless of higher prices for imported goods and leave it to states to ban or allow gay marriage.

The clarity of the choice is all the more striking when compared with the 2000 election. In it, Republican Bush and Democrat Al Gore aimed for the political center, muddling their differences as they vied for swing voters.

Shocks and bumps

What changed to produce today’s once-in-a-generation turning point?

As in the 1980 and 1932 elections, the political system experienced a shock.

In 1980, the country was suffering economic stagnation and the humiliation of its embassy personnel held hostage in Iran. Pious Democratic President Jimmy Carter offered a stay-the-course approach and painted Ronald Reagan as a dangerous radical. Reagan offered voters change, along with an easy smile and upbeat manner.

In 1932, the Great Depression was the shock. Republican Herbert Hoover was the stay-the-course candidate and Gov. Franklin Roosevelt of New York was the fresh, silver-tongued alternative. While Roosevelt sounded moderate as a candidate, he had a record as a government activist that he returned to after winning the White House.

In 2004, the country has been attacked and has lost 2.2 million jobs, the worst performance since Hoover’s term. Bush’s reactions to those shocks coaxed to the forefront a sharply conservative philosophy largely obscured in the 2000 election.

Democrats draw the line

This time around, Democrats have rebelled after going along with Bush on the war in Iraq, revamping education and other issues. Many of them blamed their 2002 midterm congressional losses on their party’s acquiescence to Bush. Their anger, at Bush and their own party, fed former Vermont Gov. Howard Dean’s early run for the Democratic presidential nomination. It also forced Democratic candidates to emphasize their opposition to Bush at every opportunity.

In defining himself against Bush, Kerry wouldn’t go as far as Dean. But he did adopt much of Dean’s more aggressive challenge to Bush, most notably by criticizing the Iraq war. “We can’t beat Bush by being Bush-lite,” said Kerry, who in 2003 had the most liberal voting record in the Senate, according to the National Journal’s respected ratings.

And the threat of losing votes on the left to independent candidate Ralph Nader is also likely to keep Kerry stressing differences with Bush, according to Betty Glad, a political scientist at the University of South Carolina.

With the two major candidates eager to highlight their differences without seeming dangerous — a la Barry Goldwater in 1964 and Reagan in 1980 — each will seek to define the other as outside the mainstream.

‘No centrism here’

Bush, the incumbent, is largely defined by his record. His new television ads this week notwithstanding, all that can change his image are events, such as a terrorist attack, developments in Iraq and the economy. His standing is “mostly based on things outside his control,” said Joe Lockhart, who was press secretary to President Clinton.

Kerry remains largely unknown to most Americans. He’ll spend the spring trying to introduce himself to voters as a decorated Vietnam War veteran with a plan to defend the country from terrorists, restore international alliances and expand the economy.

Bush will try to cast Kerry as an out-of-the-mainstream liberal who’s weak on defense and wants to increase taxes. Bush’s campaign strategists say their model is Clinton, who used a springtime ad campaign in 1996 to paint Republican rival Bob Dole as a reactionary conservative.

“No one really knows John Kerry,” said Scott Reed, a Republican strategist who managed Dole’s campaign. “He’s literally an unpainted picture.”

In addition, the major candidates’ differences on national security, the changing economy, the future of Social Security — even the definition of marriage — make it unlikely that they’ll be able to meet and compete in the political center.

“There’s no possibility of centrism here,” historian Dunn said.