The Democratic Convention is over. Now the Democratic candidate, John Kerry, and his running mate John Edwards, are back on the campaign trail. So is President Bush.

The stirring speeches are over and Senator John Kerry is back on the campaign trail.

"The march isn't over. The promise isn't perfected. Tonight, we're setting out again," he said. "And together, we're going to write the next great chapter of America's story."

John Kerry and John Edwards have embarked on a 21-state, 6,000-kilometer tour across the nation to persuade voters he is the best man for the job.

President Bush kept a low profile during the four-day Democratic Convention. But now he is back on the road too.

First stop was Missouri, where he talked of his stable leadership in a time of change and uncertainty.

"I'm asking for your vote because so much is at stake, prosperity and peace," he said. "We have so much more to do to move this country forward. Give me four more years and America will continue to march toward peace and better prosperity."

Security has become a key theme of both campaigns.

Senator Kerry addressed it in his speech to the Democratic Convention Thursday night.

"As president, I will fight a smarter, more effective war on terror," he said. "We will deploy every tool in our arsenal; our economic as well as our military might; our principles as well as our firepower. "

President Bush also addressed the issue of security in his campaign stops Friday.

"When it comes to fighting the threats of our world and making America safer and promoting the peace, we're turning the corner and we're not turning back," he said.

Opinion polls show the race is close. So, President Bush and Senator Kerry both are focusing on so-called "swing states" like Ohio and Pennsylvania, where undecided voters could make the difference on election day. Both candidates will be visiting those states in the coming days.