In U.S. presidential politics, it was a bad week for Republican hopeful John McCain.  On the Democratic side, Hillary Clinton and Barack Obama moved to solidify their positions as the top contenders for their party's nomination.  VOA National correspondent Jim Malone has the latest on the 2008 campaign from Washington.

It was a rough week for the McCain campaign.  Several top aides quit in a staff shakeup that followed a disappointing period of fundraising for the Arizona senator.

Just back from Iraq, McCain urged fellow senators to give President Bush's surge strategy in Iraq more time to work even as public opinion polls continued to show declining support for the war effort.

Senator John McCain talks with reporters regarding changes to his presidential campaign staff on Capitol Hill, 10 July  2007

Early on, John McCain was seen as the frontrunner for the Republican presidential nomination.  But in the latest Gallup poll, McCain is in third place, trailing former New York City Mayor Rudy Giuliani and former Tennessee Senator Fred Thompson, who has not even officially join the race.

Experts note that opinion polls conducted so early in the election campaign may not be a reliable indicator of who will actually get the party nominations.

Stuart Rothenberg publishes a political newsletter in Washington.  He traces McCain's current problems to longstanding differences with conservatives within the Republican Party.

"Conservatives never embraced him," he noted.  "They viewed him as too close to the Democrats on issues like campaign finance reform and, most importantly, immigration.  He is not the fresh face that he once was, not the reformer-outsider.  And so his fundraising problems really just reflect a deeper set of problems for the campaign."

John McIntyre is editor of the politics Web site RealClearPolitics.com.  McIntyre says conservatives have long memories when it comes to their disagreements with McCain, who also ran for president in 2000.

"And John McCain, because of how he achieved much of his popularity from 2000 to 2003, it was by beating up on President Bush and beating up on conservatives," he recalled.  "And when he ran in 2000, he ran very much going after the independent type of voter."

The latest Gallup poll has Giuliani at 30 percent, followed by Thompson at 20 percent, McCain at 16 percent and former Massachusetts Governor Mitt Romney at 9 percent.  Six other Republican contenders trail behind.

In the Democratic race, Hillary Clinton and Barack Obama remain the top two contenders in an eight-person field.

Clinton leads in the latest Gallup poll with 37 percent support among Democratic voters, followed by Obama at 21 percent, former Vice President Al Gore with 16 percent and former North Carolina Senator John Edwards at 13 percent.

Gore has said he has no plans to run, disappointing some Democrats who feel he would be the best alternative to Hillary Clinton.

Analyst Stuart Rothenberg says Clinton continues to do well in the polls while Obama has shown surprising strength in his fundraising.

"Well, she is strong," he noted.  "Her problem at the moment is that there is another strong candidate in the race, Barack Obama, who has raised boatloads of money and is a personally appealing alternative.  And if he can convince Democrats and the American public at large that he is experienced enough and that they can trust him with the job of being President of the United States, he is a serious alternative."

With Edwards slipping a bit in the polls, some analysts see a protracted battle for the Democratic nomination between Clinton and Obama in the months ahead.

Christopher Gelpi is a political scientist at Duke University in North Carolina.

"Hillary Clinton has been unable to sort of run opponents into the ground with her fundraising, which I think was her initial plan," he explained.  "And that has not worked out, that she has not become the presumptive winner that she hoped to be by now."

It remains early in the 2008 election cycle and opinion polls suggest many Americans have not yet begun to closely follow the presidential race.

But political experts say success at fundraising and organizing now will pay big dividends for contenders in January when the first caucuses and primaries are held to determine the party nominees.