"Immigration is who we are -- look around us," Clinton told a crowd of a few thousand gathered at a nature preserve.
"I think the Republicans are doing great damage to our nation by their insults and attacks on immigrants. So so as your president I will certainly work hard for comprehensive immigration reform," while preserving the executive orders Obama has used to relax deportation rules for certain groups, including those brought to the United States as children.
Clinton invoked Obama several times, usually to cheers, but hinted at ways she will differ from him. Her proposed immigration reform plan goes beyond his, and although she praised Obama's signature Affordable Care Act, as a candidate she has proposed repealing a key tax that would pay for some of those reforms.
"I'm tired of the yelling and the insults and the attacks and snide remarks about people because of their heritage or religion or who they love," Clinton said. "I don't think that's who we are."
Republican front-runner Donald Trump has said he would deport all undocumented immigrants and build a new wall across the southern border.
"I feel we are missing something right now in politics. We're not bringing people together to try to find common ground the way we need to," Clinton said. "Because there's a big group that don't want to try, because they believe they have all the answers."
Earlier Wednesday, Clinton picked up the endorsement of the International Union of Painters and Allied Trades.
"I’m feeling really lucky in Las Vegas,” Clinton joked after touring a union training and apprentice program.
“Last night was a good night. Today is just as good, getting the endorsement of this union,” Clinton said. “Doesn’t get any better than that.”
Asked whether her performance -- which was generally praised by analysts as the best among the five candidates on stage on Tuesday -- had closed the door on Vice President Biden's candidacy, Clinton demurred.
“I’m going to continue to run my campaign and make my case for my candidacy. And everyone else whether they are in or not in will have to make whatever judgment is best for them.”
Biden, whose son, Beau, died in May, has said he still has not made up his mind about running for president.
A main goal for Clinton was to calm Democratic qualms after a rocky summer of falling poll numbers and what often appeared to be a faltering response to worsening developments on reports that Clinton used a private server for her State Department e-mails and the rise of Sanders.
Clinton’s perceived weakness would be is a chief rationale for a Biden candidacy, and time is running out for his decision.
Clinton campaign chairman John Podesta said as much Wednesday, although he was careful to say that Biden’s decision must be his own.
"I think he deserved the space and the time to think that through about whether that it was best for him to begin this new challenge to try to mount a presidential campaign,” Podesta said in an interview with NBC’s Andrea Mitchell. “But I think the time has come for a decision.”
The same skills that served Clinton well on Tuesday may also be on view next week, when she goes before the House special committee investigating the 2012 deaths of four Americans in Benghazi, Libya, in the closing months of her tenure as secretary of state.
In the debate, Clinton called the committee an arm of the Republican 2016 election apparatus and all but rolled her eyes as she accused its leaders of using the panel to try to damage her candidacy. Committee Chairman Rep. Trey Gowdy (R-S.C.) insists he is seeking only to examine what happened when militants overran two U.S. compounds and how such tragedies might be prevented.
The long-planned hearing was rocked earlier this month by House Majority Leader Kevin McCarthy’s boast that the panel had, indeed, damaged Clinton’s standing.
“I’m still standing,” Clinton deadpanned Tuesday.