Clinton, speaking to a fired-up crowd at a gym in Indianapolis, hit Trump for dividing people without understanding the consequences, arguing that those actions have led to the violent protests that have occurred around some of his events.
"When you divide people against one another, you don't know what is going to happen," Clinton said of Trump. "We are seeing violence at political rallies in our country. That is the kind of thing you see on TV, you assume is far away, don't you? Well, this, this hateful talk about immigrants, about Muslims about women, I mean, enough, enough. It is not who we are."
Clinton pledged to work against Trump's "divisiveness" and "hateful rhetoric," a subtle nod to the fact that the former secretary of state sees the billionaire likely ending up as the Republican nominee.
Scores of protestors took to the streets
outside Trump's event in California on Thursday, drawing out police officers in riot and tactical gear and on horseback who sought to disperse the crowd. Around 20 people were arrested after some Trump supporters left bloodied.
Clinton's campaign had largely written off the Indiana primary before Sunday. After visiting the state last week for two events tailored to the manufacturing industry, Clinton's schedule did not include a return visit until the campaign began planning Sunday's rally the day before.
The race in Indiana is close, with a recent NBC poll finding Clinton up by 4% over Vermont Sen. Bernie Sanders. But Clinton has so far run no TV ads in the state and has purchased minimal time on radio.
Clinton only subtly hit Sanders during the rally, faulting "my opponent" for his college plan, which relies on states paying a portion of money needed for free public tuition -- a tough political sell where there are Republican governors.
Clinton also used a line she has routinely deployed to hit Sanders, suggesting that the Vermont senator knows how to diagnose the problem but not how to fix it.
"Folks believe incomes haven't risen, people haven't gotten pay raises, the deck is stacked, the game is rigged. I get all of that," Clinton said. "But I don't think it is enough to diagnose the problem. We can agree on the diagnosis. We have to have solutions. We have to be able to produce results that will actually change lives."
After winning four of five primaries last week, including in delegate rich Pennsylvania, Clinton's campaign has been preparing more for their likely showdown with Trump. Most of Clinton's stump speech is now aimed at the boisterous businessman and not at Sanders, who she has taken to largely ignoring.
"My belief, after studying all of this, is you have got to look at the fine print," Clinton said of Trump and Sen. Ted Cruz's economic plans. "Somebody can say whatever they want to say, make you feel good, get you all worked up. Look at the plans. Both Trump and Cruz want to slash taxes on the wealthy, haven't we done that enough? We need to start raising taxes on the wealthy so that they pay their fair share of supporting America."
Despite filling her speech with lines attacking her Republican counterparts, Clinton closed by calling for more bipartisanship.
"We can get everything done that I am talking to you about if we work together," Clinton concluded, "If we quit being on the Republican or the Democratic team or the red team or the blue team, lets get on the American team."