By Mike Dorning

Bloomberg News

WASHINGTON — Barack Obama is about to launch a presidential campaign blitz for Hillary Clinton unprecedented in the modern era, pledging a dramatic commitment of time and resources to a contest he now unabashedly frames as a referendum on his personal and political prestige.

Obama plans to devote at least one to two days each week in October to campaign for Clinton through rallies, targeted radio and television interviews, social media outreach and fundraising, said an adviser who requested anonymity.

In addition, the president’s aides have told the Clinton campaign he would be willing to appear in television ads for her. His wife, Michelle, has already cut radio, online and TV ads for the Democratic nominee, another aide said, also requesting anonymity to discuss internal planning.

Obama’s involvement comes at a critical time, with enthusiasm for Clinton lagging behind support for Obama among the young people and minorities who helped power him to the presidency. At the start of the campaign, Clinton’s camp once questioned how closely to embrace Obama but now her aides are eager to have his help.

“From the beginning, we have been interested to have him out there as often as they can spare him between now and November,” said Clinton campaign spokesman Brian Fallon. “As we get closer to the finish line, there’s no one better to help make the closing argument than President Obama.”

Yet, at this stage in the campaign, it’s unclear whether Obama can move these voters, many of whom initially supported Bernie Sanders and who have been slow to warm to Clinton since she won the nomination.

While Michelle Obama’s speech at the Democratic convention in July was a high point of the event, Barack Obama’s was not viewed as packing the emotional punch of his prior convention addresses at a moment when these voters were listening closely. Since then, he has made clear he’s invested in Clinton’s success with a series of personal appeals for support.

Obama had long planned to campaign heavily for Clinton in the run-up to the election, but in his recent campaigning he has attacked Republican nominee Donald Trump in unusually sharp tones for a sitting president — openly stating that he doesn’t consider him qualified for the office.

And he’s made increasingly personal appeals to Democrats to turn out for Clinton. At a dinner Saturday night, Obama told the Congressional Black Caucus that it would stain the legacy of the country’s first African-American president if blacks didn’t vote in large numbers for Clinton.

“I would consider it a personal insult — an insult to my legacy — if this community lets down its guard and fails to activate itself in this elections,” he said. “You want to give me a good sendoff? Go vote.”

By entering the campaign with such intensity, Obama has cast aside any pretense of remaining above the partisan fray. His activity reflects a pragmatic recognition of the importance the election outcome holds for cementing both his policy achievements and his place in history.

The “defining principle” of Trump’s campaign, Obama said at the black caucus dinner, “is opposition to all that we’ve done.”

The president will be a regular presence in electoral battlegrounds during the remaining weeks of the campaign. Vice President Joe Biden will also be on the campaign trail on Clinton’s behalf, with plans to concentrate on Ohio, Pennsylvania and Florida, an aide said.

In a memo outlining requests to Obama political aide David Simas late this summer, the Clinton campaign asked the president to concentrate on six states — Ohio, Florida, Pennsylvania, North Carolina, Iowa and New Hampshire — said a White House aide who has seen the memo. The White House is planning an itinerary along those lines but is attempting to preserve as much flexibility as possible within the logistical constraints of presidential travel to accommodate adjustments as the campaign unfolds, the aide said.

Michelle Obama, who campaigned for Clinton last week in Virginia, also plans an “active” schedule on behalf of the Democratic nominee for the remainder of the season, said Caroline Adler Morales, the first lady’s communications director.

The unusual level of Obama’s engagement in the campaign reflects a unique confluence of circumstances in the post-World War II era. His relatively strong public approval rating — 52 percent in Gallup polling Sept. 12-17 and reaching the high 50s in some other recent surveys — is better than all but three predecessors at this stage of their presidencies: Dwight Eisenhower, Ronald Reagan and Bill Clinton.

Those three presidents all had good reasons to avoid a large role in the campaigns to choose their successors. Clinton was tainted by the Monica Lewinsky scandal and Ronald Reagan by the Iran-Contra scandal, which included lingering questions about the role of the Republican nominee to succeed him, his vice president, George H.W. Bush. Eisenhower showed public disdain for his party’s nominee, then-Vice President Richard Nixon. He was famously unable to name a single contribution Nixon had made to his administration when asked at a news conference.

The current campaign also pits a Democratic nominee who by her own admission isn’t a talented orator against a Republican who has shown a genius for capturing attention.

“Donald Trump is a candidate who has shown an ability to take up a huge bandwidth in daily coverage and the president of the United States is one of the few people who has the platform and prestige to break through Trump’s dominance of the media,” said Geoffrey Garin, a pollster who works for Priorities USA, a super PAC backing Clinton’s campaign.

Obama and his wife will concentrate on fanning enthusiasm among the coalition of minorities, young people and liberals he assembled to twice win the presidency.

“A core part of the president’s message when he’s on the campaign trail will be focused on the importance of registering to vote, the importance of early voting and the importance of ultimately going to the polls on Election Day,” said Jennifer Psaki, the White House communications director.

Though the tone of Obama’s comments has become more vehement as the election nears, his role reflects a strategic choice the White House made long before the Republican nominee was apparent and draws on a cold-eyed assessment of both his political strengths and Clinton’s weaknesses.

Democrats close to Obama confided more than a year before the election that he planned a more active role in the final stages of the election campaign than any recent president had attempted on behalf of a would-be successor. Obama and his aides believed that concentrating on the final months would be most helpful for bolstering voter turnout while keeping the president clear of party primaries.

He remains more popular than Clinton with key Democratic groups. In the Gallup Poll, his job approval was 65 percent among 18- to 29-year-olds, 66 percent among non-whites and 91 percent among African-Americans.

“The arithmetic of the election at this stage comes down to Clinton’s ability to maximize her support from people who voted for Obama in 2012,” Garin said. “While she has an opportunity to reach out to some Romney voters who are alienated from Trump, the vast majority of the Clinton vote will come from people who supported Obama in 2012.”