Democratic presidential candidate Hillary Rodham Clinton on Tuesday took four out of the five presidential contests up for grabs.

Clinton's victories in Ohio, Florida, Illinois and North Carolina nearly doubled her delegate lead against her primary rival, Vermont Senator Bernie Sanders.

Appearing in West Palm Beach, Florida, Clinton told a boisterous crowd of supporters that she was “moving closer to securing the Democratic Party nomination and winning this election in November.”

Clinton is narrowly leading in Missouri, but the vote there is so close that a recount is possible.

Tuesday's victories came just a week after Sanders won a stunning upset in Michigan.

On the Republican side, Donald Trump took three states – Florida, Illinois and North Carolina – while Ohio Governor John Kasich won his home state. Missouri is also too close to call for Republicans, but Trump is currently leading.

Trump's win in Florida pushed Florida Senator Marco Rubio out of the race.

(Related: Marco Rubio ends presidential campaign after losing Florida primary.)

Clinton criticized the GOP frontrunner in her victory speech.

“When we hear a candidate for president call for rounding up 12 million immigrants, banning all Muslims from entering the United States, and he embraces torture, that doesn't make him strong, it makes him wrong! … To be great, we can't be small, we can't lose what made America great in the first place,” she said, a reference to Trump's campaign slogan, “Make America Great Again.”