With less than seven months until Election Day, the three major U.S. presidential candidates each have their own strategy for winning the White House in November.  VOA National Correspondent Jim Malone has a look at some of the strengths and weaknesses of all three candidates.

For the moment, Republican John McCain has an advantage over Democratic rivals Barack Obama and Hillary Clinton.

McCain has effectively secured his party's presidential nomination and can focus on fundraising and preparing for the general election campaign that begins in September after the nominating conventions are over.

McCain continues to make victory in Iraq the centerpiece of his campaign, and he will continue to tout his long experience in foreign policy and national security.

"By giving General Petraeus and the men and women he has the honor to command the time and support necessary to succeed in Iraq, we have before us a hard road, but it is the right road, and it is necessary and just," he said.

McCain's biggest obstacle to winning in November may be a public yearning for change.  A recent poll found 81 percent of those asked believe the United States is on the wrong track, and a weak economy is usually bad news for the party that holds the White House.

"I would be very, very nervous about a looming environment that looks to be preparing the country for change," said Tom DeFrank, who is Washington bureau chief for the New York Daily News and a guest on VOA's Issues in the News program.  "The country wants a lot of change, and when the country is ready for change, they do not usually leave the party in power in power."

The path to victory for both Democratic contenders is more complicated, because neither has yet secured enough delegates to claim their party's nomination.

Barack Obama leads in the delegate count and in the popular vote from the primaries and caucuses so far, and most experts now give Hillary Clinton only an outside chance of catching up in either category.

Both Democrats sharply disagree with McCain's view on Iraq and have proposed a phased withdrawal of U.S. troops.

Both Democratic contenders also campaign against one another with an eye toward the general election.

Obama presents himself as a unifier who can draw support from independents and even some Republicans.

"We cannot afford another four years of Bush policies, and that is what John McCain is offering, and that is why I know we will come together this fall to take this country back," he said.

Senator Clinton counters that her experience in Congress and as First Lady would make her the stronger Democratic candidate against Republican John McCain.

"I can win.  I know I can win," she said.  "That is why I do this every day, and that is what my campaign is about.  I am in it to win it, and I intend to do just that."

Both Democrats have demonstrated strengths in appealing to various voting groups.

"You have to understand that Senator Clinton has been performing much better among certain kinds of voters.  Latino voters, women voters, older voters and downscale voters, partisan Democrats who come from less affluent families," said Stuart Rothenberg, who publishes an independent political newsletter in Washington. "Senator Obama has been doing very well with independents, with younger voters, with of course African-Americans, and with upscale voters, high-education, high-income voters."

Experts say both Democrats must do a better job of broadening their appeal to win their party's nomination and to be competitive against McCain in the general election.

Peter Brown, who is with the Polling Institute at Quinnipiac University in Connecticut, says recent surveys in the key states of Florida, Ohio and Pennsylvania suggest that Barack Obama needs to boost his support among working-class white voters.

"Roughly one in five Democrats in each of these states say they will vote for McCain against Senator Obama, whereas only less than one-in-10 Democrats say they will vote for McCain versus Senator Clinton," he explained.  "That is a pretty significant drop-off."

On the other hand, Brown says Hillary Clinton faces a different challenge.  Clinton has the highest negative ratings of any of the major candidates and some Republicans believe she could become a uniting force for their party if she becomes the Democratic nominee.

"There are very few Americans who do not have a pretty firm opinion about Senator Clinton," he added.  "People know what they think about her.  She has been an icon in American politics since 1992.  That is a long time."

Given the strengths and weaknesses of the three contenders, it should come as no surprise that public opinion polls suggest a very close race in November between McCain and either Obama or Clinton.