Haley took clear aim at the GOP front-runner, discussing her family's immigrant experience while warning against rhetoric that would threaten "the dream that is America" for others.
"During anxious times, it can be tempting to follow the siren call of the angriest voices," Haley said from the governor's residence in Columbia. "We must resist that temptation. No one who is willing to work hard, abide by our laws, and love our traditions should ever feel unwelcome in this country."
Haley never mentioned Trump by name, but the implication was clear. The billionaire, who has led the Republican race in most national polls for months, said after the Paris terror attacks he would consider creating a national database of American Muslims and later called for a temporary halt to Muslims entering the United States.
Speaking to reporters in South Carolina a day after Trump proposed the ban, Haley dismissed it as "unconstitutional" and "an embarrassment" to the GOP.
"It defies everything that this country was based on," she said. "It's just wrong."
While those remarks passed mostly without comment in December, conservatives late Tuesday night lined up to take shots at Haley, with CNN political commentator Amanda Carpenter describing
her speech as "GOP self-loathing."
Conservative radio host Laura Ingraham expressed similar disappointment, writing that Haley had "missed her opportunity."
"Trump should deport Nikki Haley," was one in a series of unhappy tweets
from Ann Coulter, who also suggested a part of the speech roughly translated to "voters need to shut the hell up."
The apparent digs at Trump aside, Haley's remarks were light on partisan hostility as she sought to cast blame for the perceived ills of government on both sides of the aisle.
"We need to be honest with each other, and with ourselves: while Democrats in Washington bear much responsibility for the problems facing America today, they do not bear it alone," she said. "There is more than enough blame to go around."
"We as Republicans need to own that truth," Haley continued. "We need to recognize our contributions to the erosion of the public trust in America's leadership."
Haley, 43, is the daughter of immigrants and the first Indian-American woman to serve as governor of a state below the Mason-Dixon line. Her status as a rising star and steely politician was solidified during a trying summer, as she managed her state's response to the church massacre in Charleston and championed the removal of the Confederate flag, which she described on Tuesday as "a symbol that was being used to divide us" from state grounds.
Haley framed her experience in the aftermath of the shootings in contrast to what she described as "chaotic unrest in many of our cities."
"Our state was struck with shock, pain, and fear," she said. "But our people would not allow hate to win. We didn't have violence, we had vigils. We didn't have riots, we had hugs."
First elected in 2010, Haley's performance in South Carolina has earned her a place atop the list of potential Republican presidential running mates and fans across the country, including the most powerful man on Capitol Hill.
"If you want to hear an inclusive leader who's visionary, who's got a path for the future, who's brought people together, who's unified, it's Nikki Haley," Paul Ryan, the Republican House speaker, told CNN's Jake Tapper Monday on "The Lead."