he sensation of the 1896 presidential campaign was William Jennings Bryan, the Democratic nominee. At his party's convention in St. Louis, he electrified the delegates with a speech about inflation - specifically, about increasing the nation's money supply by abandoning the gold standard and permitting the coinage of silver.
''We have entreated, and our entreaties have been disregarded; we have begged, and they have mocked when our calamity came. We beg no longer; we entreat no more; we petition no more. We defy them. ...! We will answer their demand for a gold standard by saying to them: You shall not press down upon the brow of labor this crown of thorns, you shall not crucify mankind upon a cross of gold!''
The speech set the convention aflame. For nearly an hour, frenzied delegates cheered, parading Bryan around the floor on their shoulders. And that was just the start. Bryan barnstormed the country, talking incessantly about monetary policy and national prosperity. He traveled 18,000 miles, and gave more than 600 speeches. The passion he ignited was astonishing. ''A fanaticism like the Crusades,'' Kansas editor William Allen White (a Republican) called it.
It is impossible to imagine a modern audience being swept away by a speech on currency. But then, it is impossible to imagine a modern presidential candidate delivering such a speech. To run for the White House today is to sedulously avoid talking about issues, and to resort instead to catchy themes and focus-group-tested slogans.
Look around. George W. Bush wants Americans to know that he believes in ''compassionate conservatism,'' but he deflects all calls to explain what that might mean. He has no interest, he tells an interviewer, in ''sitting down and reading a 500-page book on public policy or philosophy or something.'' To Bush, it would seem, policy is for wonks.
Elizabeth Dole would like to be the first woman president, but says little to distinguish herself from the guys. She speaks from an unvarying script. ''Doonesbury'' has lampooned her for robotically answering questions with bromides. If she has any new ideas, she isn't telling. Mostly, she dishes up cliches. ''Our people are looking for leaders.'' ''I am not a politician.'' ''I have the vision.''
In virtually every public appearance, Vice President Al Gore ominously utters the words ''risky tax scheme.'' He has been chanting that mantra since 1996; in his debate with Jack Kemp, he chanted it eight times. Then, it was a put-down of Bob Dole's proposed 15 percent tax cut; now it's a put-down of the tax cuts pending in Congress. The budget deficit that made tax relief ''risky'' in 1996 has turned into a budget surplus today, but Gore sees no need to change his tune. Nor does he see a need to lay out his own views on taxation. His pollsters tell him to say ''risky tax scheme.'' So he says it, over and over and over.
All presidential campaigns have policy advisers, but policy is less and less a part of presidential politics. Its place has been taken by poll results, advertising, and fund-raising. ''Campaigns rarely make or propose policy these days,'' writes Daniel Casse, who worked for Lamar Alexander and Dole in 1996. ''It is considered too risky an undertaking. Ideas still have consequences, but that may be the reason presidential campaigns keep a safe distance from them.''
Casse's article, ''The Quadrennial Fear of Ideas,'' appears in the new issue of Policy Review. Looking back at 30 years of presidential races, he remarks how rare it has become for a presidential nominee to run on a clear and forceful agenda.
Polling has changed everything. The media demand specifics from candidates, but polls never show that those are what the public wants. Voters ''invariably list `the economy,' `drugs and crime,' or `education' as the most important issues facing the nation,'' says Casse. Instead of treating this data as mere sentiment, campaign gurus take it as a mandate, concluding ''that their candidate must run as `the education president' or mention the nation's `moral crisis' prominently in every speech.''
Ideas have all but vanished from national campaigns, supplanted by atmospherics and polished catch phrases. In 1980, as Jimmy Carter's reelection effort foundered, pollster Pat Cadell wrote a long memo on how to reverse the downward drift. ''People must be given a positive reason to vote for Jimmy Carter,'' it said. Yet nowhere did Cadell suggest what that positive reason might be.
In 1992, President Bush's strategist Robert Teeter charted a reelection course that steered clear of forthright policy initiatives. He proposed to beat Bill Clinton with themes, such as ''leadership'' and ''trust,'' that did well in the polls. At one meeting, Teeter distributed a chart explaining the Bush campaign strategy. At its center was a box titled `message.' The box was empty.
Campaigns don't have to be empty - Ronald Reagan's 1980 run was packed with policy ideas, from supply-side economics to hemispheric trade. But it was a one-time exception. In 1984, the Reagan campaign steered clear of substance, relying on ''Morning in America'' and feel-good TV spots to win reelection.
It isn't going to change, no matter how many pundits urge the candidates to stop being so vague. And really, who can blame them? In 1896, William Jennings Bryan lost. He was vanquished by Republican William McKinley, who spent the campaign on his front porch in Canton, Ohio, reciting empty platitudes.
Jeff Jacoby is a Globe columnist.
