"God bless Kansas," the Texas senator declared during a rally in Coeur d'Alene, Idaho. "The scream you hear, the howl that comes from Washington D.C., is utter terror at what we the people are doing together."
The Texas senator was leading Trump by more than a 2-to-1 margin in partial returns in Kansas. He attributed his strong showing to conservative coalescing behind his candidacy.
Saturday's GOP races also included Maine, Kentucky and Louisiana, while Democrats voted in Nebraska, Kansas and Louisiana. These states were largely overshadowed by Super Tuesday contests in the rear-view mirror and critical contests soon to come. But with front-runner Trump yet to win states by the margins he'll need in order to secure the nomination before the GOP convention, every one of the 155 GOP delegates at stake on Saturday was worth fighting for.
With the GOP race in chaos, establishment figures frantically are looking for any way to derail the billionaire businessman, perhaps at a contested convention if no candidate can get enough delegates to lock up the nomination in advance. Party leaders — including 2012 nominee Mitt Romney and 2008 nominee Sen. John McCain — are fearful a Trump victory would lead to a disastrous November election, with losses up and down the GOP ticket.
"Everyone's trying to figure out how to stop Trump," the billionaire marveled at an afternoon rally in Orlando, Florida.
Count Wichita's Barb Berry among those who propelled Cruz to victory in Kansas, his fifth win of the nominating race. Cruz had won Alaska, Oklahoma, Iowa and his home state of Texas.
"I believe that he is a true fighter for conservatives," said Berry, a 67-year-old retired AT&T manager. As for Trump, Berry said, "he is a little too narcissistic."
It was anger that propelled many of Trump's voters to the polls.
"It's my opportunity to revolt," said Betty Nixon, a 60-year-old Trump voter in Olathe, Kansas. She said she liked the businessman because "he's not bought and paid for."
Overall, Trump has prevailed in 10 of 15 contests heading into Saturday's voting. Florida Sen. Marco Rubio had one win in Minnesota.
Ohio Gov. John Kasich also bid for Republican votes. Rubio and Kasich both had higher hopes for winner-take-all contests on March 15 in their home states.
On the Democratic side, Clinton hoped that strong support among African Americans in Louisiana would propel her to victory. Vermonter Sanders, trailing far behind Clinton in the delegate count, had higher hopes of making progress in Nebraska and Kansas, where the Democratic electorate is less diverse.
Tara Evans, a 52-year-old quilt maker from Bellevue, Nebraska, said she was caucusing for Clinton, and happy to know that the former first lady could bring her husband back to the White House.
"We'd be getting two for the price of one," she said. "I like Bernie, but I think Hillary had the best chance of winning."
Heading into Saturday's round of voting, Clinton had 1,066 delegates to Sanders' 432, including superdelegates — members of Congress, governors and party officials who can support the candidate of their choice. It takes 2,383 delegates to win the Democratic nomination. There were 109 at stake on Saturday.
Kasich, lagging far behind among the Republicans, acknowledged that a sure way to grab the spotlight for his campaign would be to hurl insults at Trump. But he wasn't biting.
"I'm with Harry Potter: I'm not going to the dark side," he told reporters after a rally in Traverse City, Michigan, where Kasich hopes for a strong showing in Tuesday's primary.
Rubio, for his part, has had no qualms denouncing Trump as a fraud and a "con artist."
"It's not enough to say, 'Vote for me because I am angrier and over the top and am going to do and say things no one is going to do,'" he told conservatives at a conference outside Washington.
Trump, intent on denying Rubio a crucial Florida win, had the thousands at his Orlando rally swear to give him their ballots.
With early voting already under way in the state, Trump told them: "Do it now. Do it today. Do it tomorrow. ... Remember, you all swore, you're voting for Trump, you can't change."
Cruz will collect at least 17 delegates for winning the Republican caucuses in Kansas, and Trump will win at least six.
In the overall race for delegates, Trump led with 335 and Cruz had 248. Rubio had 110 delegates and Kasich had 25.
It takes 1,237 delegates to win the Republican nomination for president.
Ahead of a debate Sunday night in Flint, Michigan, Clinton met with about 20 African-American ministers in Detroit on Saturday and said "the future" of the Supreme Court was on the ballot in November's general election.
Benac reported from Washington. Associated Press writers Bill Barrow in Jacksonville, Florida; Catherine Lucey in Detroit; Melinda Deslatte in Baton Rouge, Louisiana; John Hanna in Olathe, Kansas, and John Flesher in Traverse City, Michigan, contributed to this report.