As the National Democratic Convention winds down the end of this week, pundits are saying once again that the presidential nominees — Democrat John Kerry and Republican George W. Bush — have to give gangbuster convention speeches this summer.

Kerry has to "define" himself for the American people, they say, and "close the deal" to show himself acceptable as a world leader.

Bush must justify the war in Iraq and make people feel he's not only a strong leader but a wise leader.

And so on and so on.

Actually, in my view, national convention speeches don't win or lose elections.

I've been going to the conventions since 1988, skipping this year's as other good Deseret Morning News reporters get a chance to experience and report on the meetings.

And the hype that reporters and pundits place on the speeches just gets higher and higher.

Truth is, all the candidates usually give good speeches. They get a bounce in the polls after their conventions end because they've been dominating the news for a week or more.

And then the bounce usually goes away.

And elections are won and lost at other critical times in the campaigns.

Conventions can create a buzz, true, a general feeling across the country.

At the 1992 Democratic convention in New York, the Clintons and Gores were seen as young, dynamic couples, a real contrast to then-President Bush and his vice president. (Do you even remember who that was? Dan Quayle. Enough said.)

And the bus tour Clinton and Gore made right after the convention pushed Clinton ahead to stay.

But besides that example, you would be hard-pressed to look at a convention that really made a large difference in the final outcome.

Even convention mistakes aren't usually fatal.

In Atlanta in 1988, the Democrats decided to showcase a rising star — the then-governor of Arkansas.

Clinton's speech was only OK, but it lasted something like an hour, way over the time given to him. The media panned him. And he only came back to win the nomination in 1992 and two presidential elections. (Clinton gave a very good, and much shorter, speech this past week.)

This column goes to press before Thursday night's convention speech by Kerry. So I can't critique him here. I'm guessing he'll do OK, like the other professional politicians/presidential nominees have before him.

Is it an important speech? Of course.

But I don't agree that he has 45 minutes or so to "close the deal" and convince all of America that he can be a strong leader.