Opposition Democrats gather July 26 in Boston to formally nominate Massachusetts Senator John Kerry as their party's nominee for President of the United States. Republicans will do the same for President Bush in New York City at the end of August.

Public opinion polls suggest a lot of Americans still do not know Senator John Kerry very well, even though he will formally accept the Democratic Party's presidential nomination on July 29.

Democratic Party Chairman Terry McAuliffe says the focus of the convention, beginning July 26 in Boston, will be on re-introducing Senator Kerry and his vice presidential running mate, Senator John Edwards, to the American people.

"And we will use those four days in Boston to introduce to America John Kerry and John Edwards to talk about their backgrounds, their strengths and their vision for what they are going to do to get this country moving again," said Mr. McAuliffe.

Terry McAuliffe says the theme of this year's Democratic convention will be "stronger at home and respected abroad."

Senators Kerry and Edwards will give the main speeches at the convention. Other prominent speakers include former Presidents Jimmy Carter and Bill Clinton, and former Vice President Al Gore. In addition, there will be a tribute to longtime Massachusetts Senator Ted Kennedy.

Republicans are gearing up for their own four-day convention at the end of August in New York City. Their list of prime speakers includes California Governor Arnold Schwarzenegger, Arizona Senator John McCain, former New York Mayor Rudy Giuliani and Vice President Dick Cheney. President Bush will speak when he accepts re-nomination for a second term on the final night of the convention on September 2.

The Republicans are expected to focus on the president's record of leadership in the war on terrorism and his stewardship of the improving domestic economy.

American political conventions date back to the 1830's and brought party activists together to nominate presidential candidates for more than 100 years.

In the modern era of conventions, party activists and delegates come together to rally behind a candidate chosen through the lengthy series of state primaries and caucuses.

Washington-based political analyst Stuart Rothenberg says the main role the conventions now perform is to act as a sort of four-day broadcast advertisement for the party nominees.

"These are now media events," said Mr. Rothenberg. "They are opportunities for the presidential candidate, not for the party, but for the presidential candidate to showcase himself and his ticket and to deliver the message that he wants that will ultimately be the general election message."

Because the modern political convention is so predictable and scripted, experts say the conventions have less impact on voters than they used to.

But the political parties try to put on successful conventions to give their presidential candidates a boost heading into the general election campaign that culminates this year on Election Day, November 2.

Historically, candidates have gotten a boost in public opinion polls of 10 percent or more from their conventions. Political experts call this a convention bounce. But this year could be different.

"I think in this very closely divided electorate that we have, it is probably unrealistic to expect either Kerry or Bush to get much of a bounce from their conventions," said Karlyn Bowman, an expert on public opinion with the American Enterprise Institute here in Washington.

Historically, the political conventions have been a magnet for protests of all sorts. This year, security officials are particularly focused on the Republican Convention in New York, where tens of thousands of anti-Bush protesters are expected to gather during the last week of August.