President Obama returned to Illinois where he served as state senator before launching his bid for the White House to urge for a better approach to politics. Addressing lawmakers in Springfield, Obama reflected on his years as president and said one of his few regrets was that he didn't do more to reduce the meanness in politics. (Reuters)

SPRINGFIELD, ILL. — President Obama returned to the place where he launched his first White House bid and delivered an impassioned and personal speech in which he asked, occasionally even pleaded, with his fellow citizens for a more civil and respectful political debate.

Obama warned Wednesday that Americans' sense of unity and common purpose was being “threatened by a poisonous political climate that pushes people away from participating in public life. It turns folks off. It discourages them and makes them cynical.”

His remarks were fueled by his personal regret that politics have become more divisive during his time in the White House. "It’s been noted often by pundits that the tone of our politics has not gotten better since I was elected; it’s gotten worse," Obama said during an address at the Illinois State Assembly, where he served as a state senator from 1997 to 2004.

He also seemed moved to action by his  alarm at the angry and polarizing language of the campaign to replace him.

“We can’t move forward if all we do is tear each other down,” Obama said. “And the political incentives as they are today too often reward that kind of behavior.”

"There's still a yawning gap in the magnitude of our challenges we face and the smallness of our politics," Obama said.

Obama's address came nine years to the day on which he declared his candidacy for the presidency outside the Old State Capitol building. And it came a day after business tycoon Donald Trump, whose anti-Muslim and hard-line immigration rhetoric have drawn rebukes from Obama, easily won the New Hampshire Republican presidential primary.

Obama was greeted warmly on his return to his political roots, and he returned the love: name-checking colleagues and recalling humorous and humbling moments from his time in the legislature. He emphasized that despite the political battles Democrats waged with Republicans, many of them considered each other friends.

"We didn't call each other idiots or fascists who are trying to destroy America," Obama said, recalling the lawmakers' regular bipartisan poker games. He added that they would not compromise their principles, but they were "practical when we needed to be. We'd fight like heck on one issue and shake hands on the next."

"That's why," he continued, "I always believed so deeply in a better kind of politics. … There was no problem we couldn't solve together."

The symbolic setting in the ornate chamber, with a portrait of Abraham Lincoln on the wall, made clear that this president, in his final year, will not be content to sit on the sidelines of the race to replace him. Although he has remained cautious about engaging directly in the day-to-day 2016 campaign, notably declining to make an endorsement in the Democratic primary, Obama has sought to counter critiques of his record by highlighting progress of his agenda, including the economic recovery, expansion of health care coverage and combating climate change.

He made several oblique references to the campaign during his address. "Instead of the most extreme voices or most divisive language or who is best at launching schoolyard taunts, we should insist on a higher form of political discourse ... one based on respect," Obama said. He also declared, "I am a progressive Democrat. I'm proud of that," perhaps in response to Sen. Bernie Sanders of Vermont, running for the Democratic nomination, who has questioned the progressive credentials of the president and Sanders's rival, Hillary Clinton.

The trip to Springfield kicked off a week-long trip that will include several fundraising events in San Jose and Los Angeles for the Democratic Party. During his time in California, Obama also will appear on Ellen Degeneres's TV talk show and play host to a summit of Southeast Asian leaders at Sunnylands retreat in Rancho Mirage, Calif.

Obama's bid to shape the national debate will test his own willingness to temper his rhetoric, which has flared up at times when he has addressed Democratic supporters. Last November, for example, the president ribbed Republican presidential candidates for complaining about tough questions from CNBC moderators of a GOP debate.

"They say, 'When I talk to Putin, he’s going to straighten out. ...' And then it turns out they can’t handle a bunch of CNBC moderators?" Obama said during a fundraising stop at Richard Rodgers Theatre in New York. "If you can’t handle those guys, I don’t think the Chinese and the Russians are going to be too worried about you."

Asked if Obama would pledge not to attack Republicans, White House spokesman Eric Schultz said Wednesday: "The combative nature of our politics is not new. That goes back centuries. … What I do think the president will discuss is over the past few years our political system has become more polarized.”

In 2007, Obama launched his campaign with an outdoor rally of thousands who braved the February cold to watch his announcement, which featured the young U.S. senator from Illinois accompanied by his wife, Michelle, and two young daughters.

Obama cited the words of another Illinois lawyer who went on to the White House, reminding his audience that Lincoln, during an address at the Old State Capitol building, had called on a house divided to stand together. He echoed that again in his speech Wednesday.

The president was clearly at ease. He joked with Illinois state Rep. Ken Dunkin (D), who angered his own party by missing a key vote to override Republican Gov. Bruce Rauner's veto of a labor bill. Obama said that compromising with the opposing party "doesn't make me a sellout to my own party."

"Heck, yeah," someone shouted from the floor.

Obama responded:  "We'll talk later, Ken." The audience exploded in laughter and applause, and Dunkin stood and saluted the president.

As a state senator, Obama worked on a bipartisan project to reform ethics and campaign finance laws, and one of his GOP colleagues, former state senator Kirk Dillard, filmed a campaign advertisement for Obama in 2007. Dillard, who was in the audience here, later signed on as a delegate for Obama's 2008 presidential campaign rival, Sen. John McCain (R-Ariz.).

Yet Obama's return to the state assembly also highlighted how the president, by his own admission, has fallen short of his goals. If a core promise of Obama's 2008 campaign was to bridge the political divide in Washington, those divisions have only appeared to have grown worse, contributing to the dysfunction in the nation's capital. In his State of the Union address last month, Obama said one of the biggest regrets of his presidency was that "the rancor and suspicion between the parties has gotten worse instead of better."

That has been reflected in Springfield, where an eight-month budget standoff between the Republican governor and Democratic-controlled legislature has thrown the state into a crippling financial crisis.

After arriving in Springfield, the president made a stop for take-out at The Feed Shop, a deli in the shadow of the Old State Capitol. Outside, he shook hands with passersby and reached across a rope to hug Dave Sullivan, a former Republican state senator with whom Obama had worked during his time in the legislature. They chatted warmly before the president returned to his motorcade, without answering questions from reporters about Trump winning the New Hampshire primary.

Still, even as he talked about the need for compromise, Obama lobbied for new measures to make it easier for more people to vote in elections and for the need to eliminate gerrymandering in congressional voting districts, including in his home state. Republicans in the chamber stood first to applaud Obama on the gerrymandering, because Democrats benefit from current districts in Illinois. But the GOP members, showing there were still sharp partisan divides, reacted less enthusiastically about the voting issue.

"This shouldn’t be controversial, guys," Obama said with a laugh, "you liked the redistricting thing."