WASHINGTON » Hillary Clinton is counting on Barack Obama to win her the White House, as the one Democrat who can draw reluctant young voters, African Americans and Hispanics to the polls.

But history shows that when his name isn’t on the ballot, Obama doesn’t always deliver.

Obama hit the campaign trail for seven Democratic gubernatorial candidates in 2014; five of them lost. And turnout in five neighborhoods where he appeared that year was lower than in the 2010 midterm election.

In Maryland, one of the most heavily Democratic states in the nation, more than 8,000 people stood in line for hours before packing a high school gym in 2014 to hear Obama stump for Anthony Brown, then the state’s lieutenant governor, who was running for governor.

“You’ve got to vote,” Obama told the cheering crowd in Prince George’s County, where he had won 90 percent of the vote two years earlier. “No excuses.”

Two weeks later on Election Day, the crowd had vanished. The same high school was a polling place, but turnout dipped 2.7 percentage points from four years earlier, to 30 percent. It was half what it was when Obama himself was first elected in 2008. Brown lost to Larry Hogan, who became only the second Republican governor in the state in nearly 50 years.

“The notion is that Obama is the best surrogate to speak to his strongest supporters to turn out in the support of others,” Lara Brown, interim director at George Washington University’s Graduate School of Political Management, said in an interview. “But part of his coalition are voters who are not necessarily reliable voters, so I think it is a higher bar for him to try to turn out his voters.”

Obama is more popular today than in 2014, with an approval rating that’s hovered near or above 50 percent this year. And he’s more invested in the 2016 election, which he considers a referendum on his presidency. He plans to spend one to two days a week campaigning for Clinton until Election Day, the White House has said.

Part of Obama’s mission is to increase enthusiasm among “African Americans, young people, and people of all ages who need an extra boost to remember what is at stake,” said White House spokeswoman Jennifer Friedman.

Part of Obama’s challenge is that while much of his base turned out for him, personally, the voters have no particular attachment to politics. First-time voters “caught up in the zeitgeist of electing and re-electing the first African-American president” are less likely to cast ballots in 2016 than habitual voters, said Andra Gillespie, who teaches political science at Emory University in Atlanta and has studied Obama’s effect on turnout. An Obama rally isn’t enough to get them to the polls for Clinton, she said.

“Rallies are great but rallies don’t vote,” Gillespie said. “What is important for campaigns to do is work on their ground game.”

As Obama’s approval ratings dipped to all-time lows in the fall of 2014, many Democratic candidates in competitive races kept the president at arm’s length, especially after he announced that his policies “were on the ballot” that November. Republicans hammered Democrats with television ads highlighting that remark.

The candidates that did invite Obama onto the campaign trail deployed the president specifically to boost turnout among the Democratic base. In each of his seven campaign appearances, Obama visited heavily Democratic communities where he had won at least 85 percent of the vote in 2012 — including wards in Milwaukee and Chicago that went 99 percent for the president.

Obama traveled to college campuses and held rallies in predominantly black neighborhoods in Chicago, Philadelphia, Detroit and Bridgeport, Connecticut, to gin up enthusiasm among the young people and minorities that had voted for him in droves. His 2014 campaign sprint offers some insight into how the Clinton team plans to utilize him over the next three weeks as it battles voter apathy.

After campaigning for Brown in Maryland in October 2014, Obama flew to his home town, where some 6,000 people awaited his arrival at Chicago State University. At the mostly black school, Obama urged voters to get their politically inactive relatives to the polls for then-Gov. Pat Quinn, who was running for re-election.

“You’ve got to find cousin Pookie,” he said. “He’s sitting on the couch right now watching football; hasn’t voted in the last five elections. You’ve got to grab him and tell him to go vote.”

Pookie stayed on the couch. Turnout in Chicago’s 9th Ward, where the university is located, fell slightly from 2010, and the city saw an overall 7 percent decline in voting. Quinn lost to venture capitalist Bruce Rauner, who became the first Republican governor of Illinois since 2003.

In Philadelphia’s Ward 47, where Obama led a November rally for gubernatorial contender Tom Wolf, voter turnout fell to 24 percent, with fewer than half the people who backed Obama in 2012 casting ballots. Wolf still managed to defeat incumbent Republican Tom Corbett, whose approval ratings at the time were among the nation’s lowest.

To be sure, Obama faced historic odds as he tried to motivate voters during a midterm election in which the majority of Americans stayed home. Nationwide, turnout fell to a 72-year low, as only 36 percent of eligible voters cast ballots.

As is typical during recent midterm elections, Republicans were more likely to vote than Democrats. Even in Portland, Maine, which saw an increase in turnout after Obama’s 2014 visit, the Democratic candidate for governor lost amid a Republican wave. Republicans also picked up the governorship in heavily Democratic Massachusetts, where Obama held no campaign events.

The political dynamic has turned sharply in Clinton’s favor over the past two weeks, though, after she bested Republican Donald Trump in their first debate and a 2005 video emerged of Trump boasting about groping women. After he said, in his second debate with Clinton, that he never committed the acts described in the video, at least five women came forward with accusations that he had groped or otherwise assaulted them.

Trump has denied the allegations. With his campaign in turmoil, he’s resorting to a turnout strategy of his own: an attempt to suppress enthusiasm and votes for Clinton by focusing on her husband Bill Clinton’s infidelities, in the hope that young, socially liberal voters unfamiliar with the former president’s sex scandals will become disillusioned.

Obama could be particularly effective at persuading black voters to cast ballots for Clinton, said Alexsis Rodgers, political director for the Virginia Young Democrats. In 2012, blacks voted at a higher rate than whites for the first time, according to Census figures.

Some young people and black voters are “a little apathetic” about this election, Rodgers said, but could be motivated by a personal appeal from Obama. Other Clinton surrogates including first lady Michelle Obama and Sen. Bernie Sanders are also trying explicitly to reach disaffected voters.

It’s especially difficult to project turnout this year, said Geoffrey Skelley, associate editor of Sabato’s Crystal Ball, the University of Virginia Center for Politics newsletter on campaigns. Polls show Americans are watching the race more closely than previous ones, but are also more turned off by what they see, he said.

When Obama was on the ballot, Obama-driven turnout was crucial, helping decide close elections in 2008 and 2012 in competitive states like North Carolina, Ohio and Pennsylvania, said William Frey, a demographer with the Brookings Institution in Washington.

Frey ran a model of the 2012 election, adjusting the turnout to 2004 levels, that determined former Massachusetts Governor Mitt Romney may have won if the Obama coalition stayed home.

“It was pretty close,” he said in a telephone interview. “Turnout made a difference.”

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(With assistance from Joshua Green)

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