"Donald Trump is running the most divisive campaign our lifetime. His message is that you should be afraid," she told a gathering of Latino activists today.
"We've got to come back twice as strong and twice as clear. We have got to say with one voice that Latinos are vital part of the American community."
A deadlocked Supreme Court decision last month effectively killed Obama's immigration plan to help some of the 11 million immigrants living in the US illegally.
Clinton has made revamping the country's immigration system a key plank of her presidential campaign. She has said she will introduce legislation during her first 100 days in office.
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Speaking at the annual convention of the League of United Latin American Citizens today, Clinton promised to create a clearer immigration system where immigrants with "sympathetic cases" or a history of community service can be eligible for special status.
"These actions are not consistent with our values," said Clinton. "I know how important family is and I want to do everything I can to keep families together."
Trump's proposals, said Clinton, would deport 16 million immigrants currently living in the United States, cost the country around USD 1 trillion in economic output and weaken a fundamental American value.
Her campaign sees Latino voters as a key piece of their electoral coalition not only for 2016 but the future of the Democratic Party. Latinos are one of the country's fastest growing demographic groups and Clinton called on them to help her party win up and down the ticket in November.