Barack Obama,Ted Strickland

President Barack Obama shakes hands with former Ohio Gov. Ted Strickland, a Democratic U.S. Senate candidate, as he arrives to speak at the Ohio Democratic Party's fundraising dinner Thursday in Columbus.

(Susan Walsh, The Associated Press)

COLUMBUS, Ohio - President Barack Obama is back on familiar political ground.

His speech here Thursday at an Ohio Democratic Party fundraising dinner kicked off two days of politicking in an important swing state that he carried in both of his White House bids.

For Obama, this is part farewell tour, part passing-of-the-torch to Hillary Clinton, his former secretary of state and would-be-successor. The outgoing commander-in-chief will conclude his trip Friday in Cleveland, with a Clinton campaign rally at Burke Lakefront Airport.

Obama's visit stands out at this point in the election season calendar because ...

1. It evoked nostalgia.

Call it Throwback Thursday. Obama addressed Ohio's Democratic faithful at the Greater Columbus Convention Center, right around the corner from Nationwide Arena, where he held a huge Election Day eve rally four years ago with Bruce Springsteen and Jay-Z.

Obama's speech Thursday was a way to thank the party activists and insiders who helped him win the Buckeye State twice and a chance to relive those triumphant campaigns. Events like this are aimed at energizing the base. And few Democrats do that as effectively as Obama.

Recent polls by Public Policy Polling and Fox News show Obama with a negative approval rating among Ohio voters likely to vote this fall. But he remains wildly popular among Democrats; 91 percent of likely Clinton voters approve of Obama's job performance.

Ohio polls have been all over the place lately as Trump reels from scandalous headlines. A Baldwin Wallace survey released Wednesday showed Clinton leading Trump by 9 percentage points in a four-way race that includes two third-party candidates. An NBC News/Wall Street Journal/Marist poll released Thursday showed Trump leading by 1 percentage point.

"Forget the polls," Ohio Democratic Party Chairman David Pepper told the dinner crowd Thursday. "This is Ohio. If you know Ohio, it's going to be close, right? President Obama showed us how to win Ohio when it's close. ... It's about our ground game."

2. Obama's visit also reaffirmed Ohio's status as a battleground.

Thursday was the first time since Labor Day that Ohio felt like a legitimate battleground state. Clinton and Republican nominee Donald Trump have disappeared from the Ohio trail at times, focusing instead on states that might be larger factors in this year's electoral math.

The Trump team refused to allow Obama, Clinton and the Democrats to have the Ohio media to themselves Thursday. Trump met with millennial voters in Columbus earlier in the day and then headed to Cincinnati for a large rally that was under way as Obama arrived at the dinner.

Ohio pols had been buzzing about this day since last week, when it became clear Obama and Trump would be campaigning in the state on the same evening. It was like this all the time in 2012. But this year - at least so far - such jam-packed scheduling has been a rarity.

One state that is getting more love this year: North Carolina. Obama already has campaigned there for Clinton twice, including one joint appearance. Pennsylvania, another battleground that Trump is targeting heavily, is the only other state where Obama has stumped for her.

3. Obama tore into Trump.

He noted last week's emergence of a 2005 video that featured Trump speaking of women in sexually aggressive terms - "things," Obama said, "that no decent person would even think, much less say, much less brag about." But the president said Republicans knew what they were getting in the New York businessman and reality TV star before nominating him.

"You claim you're the party of family values, and this is the guy you nominate? And stand by and endorse and campaign with? Until finally, at the 11th hour, you withdraw your [endorsement]? You don't get credit for that," Obama said. "You're the party that is tough on foreign policy and opposes Russia, and then you nominate this guy, whose role model is [Russian President] Vladimir Putin, the former head of the KGB? I'm sorry, what happened?"

Obama called GOP rhetoric and conspiracy theories, in this age of Trump, "a swamp of crazy that has been fed over and over and over and over again." He added later: "If you're only agenda is ... crazy based on lies, based on hoaxes, this is the nominee you get."

4. Obama gave Ted Strickland a bit of a boost.

Strickland has struggled in his bid to unseat U.S. Sen. Rob Portman. The former governor is far behind in the polls and having trouble raising money. Meanwhile, national Democrats have largely given up on him. Strickland is relying on the state party for support - and the ticket proceeds from Thursday's sold-out dinner benefit the state party's federal account.

Obama devoted a large section of his speech to promoting Strickland. He talked of him more than Clinton, whose candidacy will be the focus of Obama's Friday rally in Cleveland.

"I could not be prouder to call Ted a friend," Obama said. "There's a reason Ted has always worked to put families first. In these families, he sees his own family. ... He knows their hopes and dreams. ... Ted delivers. And when it mattered most, he had your back."

Obama also blasted Portman for supporting Trump until after the 2005 video surfaced.

"I guess it was OK when Trump was attacking minorities ... insulting Gold Star moms, making fun of disabled Americans," Obama said. "I guess that didn't quite tip it over the edge."

5. Finally, Obama's visit prompted 'third term' talk.

"Barack Obama is so desperate for a third term that he's become Defender-in-Chief for Hillary Clinton on the campaign trail, even as more evidence of her disdain for regular Ohioans leaks out every day," Seth Unger, communications director for Trump's Ohio campaign, said in a statement emailed before the president's speech. "President Obama and Hillary Clinton got America into this mess together, and Donald Trump is the only one who can stop them from further cementing their legacy of failure at home and abroad in our history books."

One final thing to consider on this score: That Public Policy Polling survey mentioned above? It asked respondents whether they would rather have Obama or Trump as president.

A majority - 51 percent - picked Obama.