So with only days before the Iowa caucuses, the main issues are: Why didn’t Howard Dean have more diversity in his Cabinet as governor in Vermont? (Sane answer no one dares utter: Racial diversity is a special challenge in a state that has a black population of one-half of 1 percent.) Why isn’t the national press paying more attention to the Rev. Al Sharpton’s campaign expenditures? (Sane answer: The press always takes it easy on a candidate who is sure to lose.) Will Rep. Richard A. Gephardt surpass Dean in the final days? (Sane answer: No one knows right now, and everyone will know Monday night, so let’s talk about something else.)

All of that is why we need to take a step back, take a deep breath and look at what the 2004 election is all about. We don’t know for sure right now, of course; the year is still young and the disposition of the war on terrorism and the state of the economy are still unfolding. But there is every reason to believe that a campaign that is ending in Iowa with a focus on very little things is actually an election about very big things. Here are some of them:

What is the nature of the American political conversation? Right now there isn’t much conversation, just a lot of folks shouting at each other or, more accurately, shouting past each other.

Richard Nixon, no avatar of civility, nonetheless opened his own presidency in 1969 by saying, “We cannot learn from one another until we stop shouting at one another — until we speak quietly enough so that our words can be heard as well as our voices.” Good lesson, seldom learned. The Democrats are showing the difficulty of having a civil civic debate — and they agree about most issues. The general election is likely to be even more caustic.

Is an American consensus a thing of the past, or is this a peculiar period of contention? Americans have been contentious before, even in times of strong presidencies that were later regarded as successful. (No one was reviled quite so bitterly as Franklin D. Roosevelt, who was a favorite of Ronald Reagan’s — even after Reagan’s political conversion.) But there is an unusual rawness to the political debate today, perhaps because, unlike other periods of history, important bedrock principles are at stake. A measure of the polarization: There were more unanimous votes among Republicans and Democrats on Capitol Hill last year than there were at any time in the modern period. Republican senators voted with their party 19 times out of 20, the highest rate in the five decades that Congressional Quarterly has conducted party-unity studies.

Has the pre-emptive strike become a conventional part of the American foreign-policy arsenal? Only in very controversial episodes have Americans initiated military confrontations without direct provocation. That is why the decision to begin hostilities against Iraq late last winter was so controversial. It spawned a worldwide debate and it provided fuel to the presidential campaign of Howard Dean, who almost certainly would not have been the Democratic front-runner in January 2004 if President Bush had not ordered the invasion of Iraq in March 2003.

A new report by the Army War College, disclosed this week, characterized the war in Iraq as “unnecessary.” But that does not quell the question. There is at least the suggestion that the strong American action in Iraq reaped dividends in Libya, North Korea and perhaps even in Iran. And the prospect that rogue terrorist groups like al-Qaida could set in motion catastrophic attacks against the American homeland, or the prospect that a nuclear power could come under al-Qaida’s sway (the ultimate Pakistan nightmare), raises the question of how a president should approach crises that were inconceivable even at the time of the passage of the War Powers Act.

How should a nation of nearly 300 million balance two competing social goods: assuring the freedom of all while preserving the liberties of individuals? This is the most difficult question of our domestic life in the age of terror. The country was founded on both of these social goods, and in a quieter age it was possible to contemplate the notion that an attack on the latter was an attack on the former. Today that is not quite so clear a notion. But the dangers inherent in curtailing liberty while seeking to preserve liberty are quite clear.

What is a presidential campaign for? At its best — and some of the best ones include the elections of 1896, 1932, 1960 and 1980 — a presidential campaign is a time for a nation to look at its past and its values, think about the future and its challenges, and marry the two. The best presidential elections are about political choice, not political personalities. The best political elections are about big issues, not small contretemps. The best presidential elections are the ones in which the big issues aren’t postponed until the next presidential election.

David Shribman is a columnist for Universal Press Syndicate.