Demonstrators gathered on a main highway in Phoenix, Arizona Saturday, blocking traffic for miles where Donald Trump staged a campaign rally.
The businessman was campaigning in the state ahead of a primary there Tuesday.
At a rally in Tucson, a protestor was being led out of the building when a man believed to be a Trump supporter attacked him.
At the same rally, Trump's campaign manager Corey Lewandowski could be seen arguing with another protestor, leading the man to punch a member of Trump's security team.
During his speech, Trump took aim at the so-called Republican establishment that has actively campaigned against him.
"They don't know what they're doing. They have no clue. They don't know how to win. They haven't won in a long time. They pick the people. They absolutely will never win with the people they talk about," Trump said. "Go out on Tuesday and vote. I will never let you down."
Meanwhile, Ted Cruz made a campaign stop in Utah.
He told reporters that voting for his rival John Kasich would inevitably lead to Donald Trump becoming this year's nominee.
Cruz says he's in the best position to beat the GOP front-runner.