WASHINGTON — Sen. Bernie Sanders has officially entered the crowded field of Democrats for the 2020 presidential nomination, noting the Democratic Party's leftward shift as a reason for a second run for the White House.

• Sen. Bernie Sanders announces 2nd run for president
• Election expert wonders how Sanders will fair in swing states
• Experts believe moderate Democrat more likely to win over voters

"We were told our ideas were radical," said Sanders in his announcement video.

Sanders notes many of his progressive views have been adopted by the party since his last run.

“Three years have come and gone, and as a result of millions of Americans, standing up and fighting back, all of these policies and more are now supported," he said.

The big question is how will more progressive Democratic challengers like Sanders and Massachusetts Senator Elizabeth Warren, who have adopted a populist policy agenda, perform in the nation's largest swing state down the line?

“They have problems. The Democratic challenge this year is to pick up the energy from the left and pick up the genuine need for reform, doing something about income inequality, racial justice, etc. without turning off a lot of white middle class voters," said Elaine Kamarck with the Brookings Institution in Washington, D.C.

In the 2018 midterm election, Democrats across the country picked up seven governorships and 40 House Seats. However, Florida Democrats came up short, which could be a foreshadowing of what is to come for 2020 Democratic contenders.

"It’ll be hard, you have to be able to hold your base and grow your base, and that is the challenge for Bernie Sanders and Elizabeth Warren," Kamarck said. "They are going to have to figure out how to talk to a broader swath of America," she explained.

Experts believe a moderate Democratic candidate is more likely to win over voters. However, in a state that has voted for every presidential winner since 1992, winning Florida isn't always the answer.

“Democrats can win the electoral college without Florida. If they take Michigan, Wisconsin and Pennsylvania, they can lose Florida and Ohio," Kamarck said.

President Donald Trump is already courting voters in the Sunshine State, making a play for the Hispanic demographic in Miami on Monday, addressing the situation in Venezuela.