Florida(ANN)- Ten Democratic presidential candidates in the US have debated onstage for the first time, as they fight to win in the 2020 presidential election and deny President Donald Trump a second term in office.

The debate was hosted by NBC News and held at the Adrienne Arsht Center for the Performing Arts in Miami, Florida.

Rising health care costs, the immigration crisis on the US-Mexico border and growing wealth inequality more than any other issues, led the first of two debates on Wednesday, with another to follow Thursday.

The Democratic contenders repeatedly attacked Trump, saying his economic policies benefited the wealthy at the expense of working Americans, and calling his border policies cruel.

Massachusetts Senator Elizabeth Warren, called for “fundamental change” across the US economy and government to address a widening income gap between the wealthy and the middle class.

“I think of it this way. Who is this economy really working for? It’s doing great for a thinner and thinner slice at the top,” Warren declared.

All the candidates supported the concept of providing universal health care, but they differed on how they would reach that goal. Several proposed abolishing private health insurance, while others favored preserving the Affordable Care Act, also known as Obamacare.

After years of defending former Democratic President Barack Obama’s landmark healthcare law known as Obamacare from Republican attempts to repeal it, Democrats have struggled during the campaign to agree on the best approach to fixing it.

Warren was the most high-profile figure in the Wednesday debate. Among the 10 Democratic candidates set to debate Thursday is former Vice President Joe Biden and Senator Bernie Sanders.

The Vermont senator has proposed a “Medicare for All” system without private insurance while Biden, who will also be debating, hasn’t gone that far.

Immigration was also among the main topics of the debate as they pointed to the harrowing photos of a drowned father from El Salvador and his toddler daughter at the Rio Grande river and blamed Trump and his policies concerning migrants crossing into the US illegally.

“Watching that image of Oscar and his daughter Valeria was heartbreaking,” said former Obama administration housing chief Julián Castro.

The candidates also turned their fire on each other, most often targeting Beto O’Rourke. The former congressman was attacked for his immigration proposals. O’Rourke says he doesn’t support fully decriminalizing border crossings at the US-Mexico border because of fears about smugglers of drugs and people.

Several of the contenders condemned at large US corporations, saying they did not pay enough in taxes, shift jobs overseas and charge too much for their products.

The debate was taking place as Trump was flying aboard Air Force One to Osaka, Japan, for a G20 summit. Shortly after the debate began, Trump tweeted “BORING!”

The sober policy discussion underscored the party’s divisions on the nation’s most pressing issues. According to a recent Gallup poll, poor government leadership, immigration, the economy and healthcare are the most important problems facing the US today.