Republican presidential contender John McCain picked up the endorsement of a former rival Thursday.  Meanwhile, Democratic candidate Hillary Clinton got some potential good news in her battle with Barack Obama.  VOA National correspondent Jim Malone has the latest on the U.S. presidential race from Washington.

McCain won the endorsement of former Massachusetts governor Mitt Romney.

During the campaign, the two were bitter rivals, clashing frequently during debates over immigration, taxes and negative campaign advertisements.

But at a joint appearance in Boston Thursday, both men did their best to put their differences behind them and unite for the good of the party.

Romney hailed McCain as uniquely qualified to lead the war on terror as president. 

"This is a man capable of leading our country at a dangerous hour," he said.  "Senator McCain understands the war we are in, the necessity of victory and the consequences of surrender."

McCain is hoping that most of the 280 delegates that Romney won before he pulled out of the presidential race last week will switch into his column, putting him ever closer to securing the Republican Party's presidential nomination.

"We know it was a hard campaign," he said.  "And now we move forward together for the good of our party and the nation, and I am very honored to have governor Romney and the members of his team at my side."

Even before the Romney endorsement, McCain had an estimated 800 delegates and was getting close to the 1,191 votes needed to win the nomination.

McCain also hopes that the Romney endorsement will win over some conservative Republicans who continue to oppose him because of his record on taxes, campaign reform and immigration.

Former Arkansas governor Mike Huckabee remains in the Republican race, but trails McCain badly in the delegate count.

Meanwhile, in the Democratic race, Hillary Clinton's campaign fortunes may have taken a turn for the better Thursday with the release of new polls in the upcoming primary states of Ohio and Pennsylvania.

The polls by Quinnipiac University in Connecticut found Clinton leading Obama by 21 points in Ohio and by 16 points in Pennsylvania.

Ohio holds its presidential primary March 4 along with Texas.  Pennsylvania will vote on April 22.

Clinton is counting on those three states to blunt Obama's momentum in the wake of his eight straight caucus and primary victories.

"We go on," she said.  "We are ready for the contests that are upcoming and the hundreds of delegates that will be in play on March 4.  We are well organized and well positioned."

The poll numbers in Ohio and Pennsylvania could give the Clinton campaign a much-needed boost after several days of disappointing news.

But political experts point out that Clinton had big leads in several other states during this state-by-state nomination campaign, only to see Obama come from behind to win.

Obama remains focused on Tuesday's primary in Wisconsin and on a Democratic caucus in Hawaii in hopes of increasing his modest lead in total delegates.

Obama is also engaging the presumptive Republican presidential nominee, Senator John McCain, during his campaign rallies, in hopes of building a sense of inevitability about his chances for the Democratic nomination.

"John McCain started attacking me on economic policy, which I thought was flattering," he said.  "It is clear he knows who his opponent is going to be and I am looking forward to a great debate."

Longtime political observer Tom DeFrank of the New York Daily News says Clinton is facing a must-win situation in Ohio and Texas in early March.

"She has to win somewhere," he said.  "He [Obama] has now won eight in a row, and that is powerful momentum.  Eight victories in a row is really compelling momentum.  Now, she does have an opportunity on the 4th of March."

DeFrank is the guest on this weekend's Press Conference USA program on VOA.

Obama is favored in Tuesday's contests in Wisconsin and Hawaii.