U.S. political candidates make great effort to get endorsements - - statements of support - - from other politicians, from issue groups, and others whose backing could bolster their campaigns for office.  In this segment of "How America Elects," VOA's Jeffrey Young examines endorsements and their value both to the candidates as well as the voting public.

The wintry weather in Cleveland, Ohio is miserable.  Nonetheless, this woman trudges from door-to-door, promoting the presidential candidate her labor union has endorsed. His victory is what matters to her, not the cold.

Political science professor Michael McDonald at George Mason University says endorsements help voters to define the candidates, "If they [voters] don't have a lot of information about the candidates, what they can use an endorsement for is to fill in some of the blanks as to what the candidate's policy positions are."

Additionally, these endorsements can project strength and other qualities.  For example, Democratic candidate Hillary Clinton sought to overcome biases against a woman being the presidential commander-in-chief of the military by collecting endorsements from at least 30 retired admirals and generals.

Candidates also seek endorsements from celebrities, hoping this will attract media attention and, hopefully, more supporters.  Media mega-star Oprah Winfrey went to Iowa ahead of its caucus voting to endorse and campaign for Democratic Party presidential contender Barack Obama.

"Over the years, I have voted for as many Republicans as I have [voted for] Democrats,” Winfrey said. “So, this isn't about partisanship for me. This is very, very personal. I'm here because of my personal conviction about Barack Obama and what I know he can do for America."

Endorsements can be invaluable to campaigns for the cash that they can bring in, as Johns Hopkins University's Ben Ginsberg observes. "Those people who are investing in campaigns, for example - - contributors - - they are looking at the pattern of endorsements because they want to be sure that they are not investing in a losing campaign," Ginsberg said.

Candidates often crave endorsements from rivals they have defeated in primary and caucus contests. It means more internal party support and, hopefully, voters. Republican candidate Mitt Romney hands over his nominating convention delegates and resources. He says, "I am honored today to give my full support to Senator John McCain's candidacy for the presidency of the United States.  I am officially endorsing his candidacy."

Candidates also seek endorsements from interest groups and labor unions, because their support includes having their members help out campaigns. That is what the Service Employees International Union did for Barack Obama in Ohio, as explained by union official Anton Famby.

"Currently right now, in Cleveland, we have a lot of our [union] members mobilized to volunteer: [To work the] phone bank, canvass - not only our own members but [also] the general public," Famby said.

But many political observers say these endorsements have little overall impact on voters, that candidates' personalities and where they stand on important issues are the determining factors in How America Elects.