Republican Ted Cruz and Democrat Bernie Sanders both scored weekend victories against their front-running rivals in a tightening race as the two major parties prepare to pick their White House nominee.
Cruz, the Texas Senator, chipped away at Donald Trump's lead by taking all 13 Colorado delegates at stake in a state Republican convention Saturday, notching his fourth win in a row against the brash billionaire with ten days to go until a pivotal primary in New York.
"Today was another resounding victory for conservatives, Republicans, and Americans who care about the future of our country," said Cruz, who had already swept the previous 21 delegates at play in Colorado through a series of county elections.
Looking ahead to the next milestone in the nomination race, Trump sought to play up his credentials as a New Yorker on Saturday with a visit to the September 11 Memorial Museum – seizing the chance to roundly criticize Cruz for his dismissive talk of "New York values."
Cruz meanwhile urged the party to rally around him as the only candidate able to beat Democratic frontrunner Hillary Clinton, warning at a Republican Jewish Coalition gathering on Saturday that Trump would face a "bloodbath" in November's general election, US media reported.
Although Trump currently leads the Republican primary race, some projections figure he would lose in a landslide in a general election matchup against either Clinton or her Democratic rival Sanders.
While it is unlikely that Cruz will reach the required number of delegates to secure the nomination at this stage in the game, he may block Trump from reaching that number either, and thereby force a GOP convention where the nominee will be decided.
Sanders, an open socialist, meanwhile pulled off a surprise win over rival Hillary Clinton in the Wyoming caucuses, his eighth victory in the last nine contests, and the last vote before New York's pivotal primary on April 19.
Although party rules in the overwhelmingly Republican state meant Sanders barely put a dent in Clinton's more than 200-delegate lead, the victory kept up the momentum for the Vermont senator.
Speaking on CBS's Face the Nation on Sunday, he said, "We are closing the gap in New York and Pennsylvania. In California. I am feeling really great, and I believe that we have a real path to victory, and that at the end of the day, we're going to win this."
Sanders – who locked horns with his rival Clinton over trade and the "Panama Papers" scandal this week – played down their increasingly personal barbs over who is more qualified to be president, saying Clinton "has enormous experience."
But he repeated questions about her judgment, criticizing her support for the American-led invasion of Iraq in 2003 and her failure to support Wall Street reform following the global financial crisis in 2008.
He also raised his central criticism of Clinton's corporate support.
"We're talking about tens of millions of dollars through her super-PAC from every special interest that you can think of from the billionaire class," he told CNN. "I have my doubts about what kind of president she would make."
Clinton on Sunday also played down the personal tone of her exchanges with Sanders, telling CNN, "I don't have anything negative to say about him."
Both Democrats are campaigning hard in New York – Clinton as a former senator from the state and Sanders as a native of Brooklyn.
"Our message is resonating," Sanders told CBS on Sunday. "People really are tired of establishment politics, establishment economics."
However, it would take a remarkable turnaround for him to win the nomination over Clinton, a former first lady and secretary of state who goes into the New York primary as heavy favorite to extend her lead in the overall race.
She leads Sanders 54-42 percent among likely Democratic voters in the state, according to Quinnipiac University polls.
New York City, America's largest metropolis and one of its most diverse, has demographics that play well to Clinton's support base among the wealthy and minorities.
Sanders, who has called for nothing short of "revolution," has attracted a large part of the youth vote, but he is faring poorly in comparison with Clinton among African Americans in particular.
AFP contributed to this report.