Nikki Haley vows to stay in race, ramping up attacks on Trump

Nikki Haley, the last Republican challenger to Donald Trump, vowed to stay in the race for the GOP nomination Tuesday, saying she feels "no need to kiss the ring." 

The former ambassador to the United Nations and governor of South Carolina said during a campaign stop in Greenville that she's "far from" dropping out of the race, regardless of an expected primary loss in her home state on Saturday. She said she would campaign "until the last person votes," noting that only four states will have held their primary contests by Saturday. 

"Dropping out would be the easy route," she said. "I've been the underdog in every race I've ever run. I've always been David taking on Goliath. And like David, I'm not just fighting someone bigger than me. I'm fighting for something bigger than myself."