ARI SHAPIRO, HOST:
Sometime soon, maybe this week, President Obama will endorse Hillary Clinton. Sounds like a no-brainer. The Democratic president wants to help elect a Democratic successor, and Clinton is now the party's presumptive nominee. But as NPR national political correspondent Mara Liasson reports, having a popular sitting president ready to campaign all-out for his party's nominee is actually kind of rare.
MARA LIASSON, BYLINE: Hillary Clinton is now the presumptive nominee of her party. In a tight race against Donald Trump with high unfavorable ratings of her own, she needs all the help she can get. And in a few days, she will officially have the support of the most valuable player on the Democratic team - President Obama. Democratic strategist Lynda Tran says he can help her in several crucial ways, starting with party unity.
LYNDA TRAN: He's somebody who Democrats of every stripe really love and respect. And so I think he's in a really great position to help her with that. And then the second point is he's clearly an effective messenger in appealing to African-American voters, to suburban independent voters - but particularly those young voters between the ages of 18 to 29.
LIASSON: Those young voters went overwhelmingly for Bernie Sanders and they've been particularly resistant to Clinton all year. Then there are all the benefits that a high-profile surrogate like President Obama can offer. Donald Trump has virtually no surrogates, high-ranking elected officials who can speak for him, defend him, reinforce his message. He's been a one-man band. Clinton says former Democratic strategist Chris Lehane has a whole stable of surrogates to help her maximize what is the single most important resource in a presidential campaign - time.
CHRIS LEHANE: A candidate can only be at one place in a one given moment. But when you can introduce the president, a first lady, a former president - who's your spouse, and yourself. That's four or five different major principles that you can put out there. You can be doing multiple fundraisers, you can be in multiple states at once. And I also think that's one of the reasons why the president is coming out so early, so that Secretary Clinton can really fully leverage that advantage.
LIASSON: This is actually the first time in a long time that a sitting president will be going all-out to help elect his successor. Ronald Reagan endorsed George H. W. Bush, but he didn't campaign the way Obama plans to. Partly because Bush wanted to establish himself as his own man after eight years as number two. And also perhaps because Ronald Reagan was already suffering the early effects of Alzheimer's disease. The situation between Bill Clinton and Al Gore was more complicated. Clinton endorsed Gore but because of President Clinton's scandals, Gore didn't ask him to campaign for him until the very end - when it was probably too late to make a difference. Chris Lehane worked for Clinton and then became Al Gore's press secretary. He remembers the huge internal debate in the Gore campaign about this.
LEHANE: President Clinton, who had - at that time had the highest job approval rating of any sitting president in their final year - also was still dealing with the baggage of what had happened with the impeachment process. He ended up being an asset in the last few weeks of the campaign but there's always been that revisionism of what if - what if he had been out there earlier? Would that have made a difference?
LIASSON: George W. Bush didn't campaign for John McCain, says Republican strategist Scott Reed - partly because Bush's approval ratings were too low to help.
SCOTT REED: Presidents can help, I think, if they're actually above 40 percent. I believe Bush was in the 30s when he was near the end of this term. The country had just gone through some very difficult times financially, and people were upset with the government. And I think McCain's view was, I've got to run this my way.
LIASSON: Hillary Clinton on the other hand has latched herself tightly to President Obama, whose national approval ratings are hovering around 50 percent. With Democrats he's nearing 90 percent. Here's Clinton at a campaign stop yesterday in California.
(SOUNDBITE OF ARCHIVED RECORDING)
HILLARY CLINTON: I want to continue and further the progress that we've made.
LIASSON: She said President Obama doesn't get the credit he deserves for saving the economy from the great recession.
(SOUNDBITE OF ARCHIVED RECORDING)
CLINTON: The president got us out of that ditch, now we've got to run with it. And I've laid out plans to do just that.
LIASSON: Even before he endorses, President Obama is already busy laying out the argument against Donald Trump. And making it clear he's chomping at the bit, eager to join the campaign. Last week, he was in Elkhart, Ind., giving a speech on the economy. He never mentioned Trump's name, but...
(SOUNDBITE OF ARCHIVED RECORDING)
BARACK OBAMA: If we get cynical and just vote our fears, or if we don't vote at all - we won't build on the progress that we started.
LIASSON: The president needs a Democrat to build on that progress, and he needs to stop Donald Trump from reversing it. Lynda Tran...
TRAN: If Donald Trump ends up in the oval office, President Barack Obama's legacy is at great risk. And in fact, I bet that this is going to be a core message that he really hammers home when he's on the trail stumping for Hillary Clinton.
LIASSON: So this fall, Barack Obama has as much on the line as does the Democratic nominee. Mara Liasson, NPR News, Washington. Transcript provided by NPR, Copyright NPR.
