The Democratic presidential nominating process is now at its halfway point, but fear over the spread of coronavirus has slowed the race for the White House to a virtual standstill, CBS News political unit associate producers Sarah Ewall-Wice and Eleanor Watson report. Right now, 25 states along with the District of Columbia, Puerto Rico, Guam and the Virgin Islands have yet to hold their nominating contests, but state and party officials are grappling with how best to address the primary process amid health concerns.

To clinch the Democratic nomination, a candidate needs to obtain 1,991 pledged delegates, just over half of the 3,979 at stake. On Tuesday, Illinois, Florida and Arizona doled out 441 pledged delegates. By CBS News estimates, on Wednesday, Joe Biden was leading Bernie Sanders in total allocated delegates, 1,093 to 802. That means 1,668 delegates, just under half of the pledged delegates available, are still up for grabs.

Five states have so far postponed Democratic presidential primaries. Ohio was slated to hold its primary on March 17, with 136 pledged delegates available. It has moved in-person voting to June 2.

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Read more on the primary shakeups and what to expect in the coming weeks here.

FROM THE CANDIDATES

JOE BIDEN

As President Trump was addressing reporters from the White House podium, Biden's campaign aimed to counter program and released a statement criticizing the president's response, CBS News campaign reporter Bo Erickson reports.

"Much has been made of changes in the President's tone in recent days," Biden said in the statement, "But with our health care system at risk, a virus spreading, our economy on the brink — and so many lives at stake — it's time to be less interested in the President's words and more focused on his actions — or inaction."

The campaign also reiterated steps Biden believes the Trump administration should be taking to address the spreading virus. His suggestions include instituting a transparent reporting process regarding testing, expanding the number of beds and facilities ready to accept sick patients and surging medical personnel to the places that need it most. Biden also blamed the lack of medical equipment on "Trump's misguided trade war with China, which led to tariffs on essential medical supplies and reduced their availability in the United States."

As Biden continues to practice social distancing at his home in Delaware, his campaign also took time after last night's latest contest to forecast his growing delegate lead over Bernie Sanders. Deputy Campaign Manager Kate Bedingfield calculated in a memo that "in order to close the delegate deficit" Sanders "would need to win every remaining contest by roughly 40 points." She also noted Biden's delegate lead at this point is three times as large as Barack Obama's was in 2008 and Hillary Clinton's was in 2016.

BERNIE SANDERS

Sanders staffers's phones were buzzing this morning and afternoon as the senator's presidential campaign prospects seemed more dire than ever. This morning, campaign manager Faiz Shakir released a statement saying, "The next primary contest is at least three weeks away. Sen. Sanders is going to be having conversations with supporters to assess his campaign."

Shakir also noted that Sanders' attention is fully focused on COVID-19. Soon after, Shakir wrote to supporters saying that Sanders and his wife Jane would be returning to their Burlington, Vermont, home tonight to evaluate the campaign's future in light of the three losses last night.

"No sugarcoating it, last night did not go the way we wanted," he wrote. Notably, this email did not contain the otherwise ubiquitous request for campaign funding. Along those same lines, it was reported today that the Sanders camp was pulling Facebook ads. Communications Director Mike Casca told CBS News campaign reporter Cara Korte that the move was to "conserve resources." That was reason enough to scramble, until an errant tweet released briefly this afternoon incorrectly stated that Sanders was suspending his campaign. That report was quickly denied to CBS News.

Here's what we know: The mathematic outlook for Sanders is bleak. To surpass Biden's delegate lead, Sanders would have to trounce Biden in an unprecedented way in primaries to come. Since that is unlikely, Sanders is now in a position to choose whether or not he fights on or throws in the towel.

Sanders is unusual in that he represents a movement as much as he does a candidacy. There are some who argue his campaign should go on so that the movement continues. Others say that carrying on a losing battle only bruises the validity of the cause. No aide or ally can predict what Sanders will do. CBS News has been told that he will consult with his family and supporters in the days or possibly weeks ahead. Watch for communication between the Sanders and Biden camps. If Sanders is to concede, he would presumably want something in return – perhaps the reassurance that his agenda, which millions support, will not be suspended just because his campaign is.

LIFE AFTER 2020

BILL WELD

Former Governor Bill Weld announced the suspension of his campaign Wednesday afternoon, the day after President Donald Trump clinched the Republican nomination, reports CBS News political unit associate producer Eleanor Watson. Weld launched his campaign last April as the first of three Republicans to issue a primary challenge to Mr. Trump.

Former Governor Mark Sanford suspended his campaign in November and former Congressman Joe Walsh dropped his bid after the Iowa caucuses. Weld won just over 9% in the New Hampshire primary, the backyard of his home state of Massachusetts, but did not gain traction in other states heading into Tuesday night's primaries. In a statement Wednesday, he thanked those who have helped him stay in the race this long and said, "Leading this movement has been one of the greatest honors of my life, and I will be forever indebted to all who have played a part."

STATE-BY-STATE

FLORIDA

Florida's preliminary election results are in, and Joe Biden beat Bernie Sanders in every one of the state's 67 counties, receiving more than a million of the 1.7 million votes cast in the state's Democratic primary. CBS News campaign reporter LaCrai Mitchell reports that amid voter safety concerns surrounding the COVID-19 pandemic, Florida's Secretary of State Laurel M. Lee called Tuesday's primary a success.

"Thanks to our 67 county supervisors of elections, their staff and thousands of poll workers, Floridians were met with professionalism in addressing concerns, and a steady commitment to ensuring eligible voters were able to vote," said Lee in a press release statement Wednesday.

Vote-by-mail and provisional ballots are still being counted but preliminary reporting shows that nearly 3 million voters cast their vote in the state's primary contest—a 16% drop in voter turnout from the 2016 presidential preference primary when 4 million voters cast their ballots. According to CBS News exit poll data, 75% of Florida voters who chose Biden decided who they'd vote for in the presidential primary earlier this month. Geographically, the former vice president had the greatest margin of victory in the traditionally Democratic southern region of the state around Miami, but in Miami-Dade County turnout was just over half of the 40% that showed up in the 2016 presidential primary.

ILLINOIS

From the unofficial number count, turnout in yesterday's primaries was 25.7%, a concrete result from a state that decided to hold its primary in the face of the COVID-19 pandemic. While more numbers from mail and early vote ballots will be coming in the next two weeks, the turnout is a definite drop from the 46.5% turnout in 2016 and the 33% average. In Chicago, where precincts started the day with missing voting machines and confusion with polling locations, overall turnout was around 31%. In Rockford, Illinois, where turnout was around 26%, Executive Director of the Board of Elections Stacey Bixby told CBS News political unit broadcast associate Aaron Navarro on Tuesday that they saw a pretty smooth, constant turnout. "I think that we're busier than we expected to be due to all of the circumstances and situations that are happening," she said. "We felt as prepared as we could be, you know, under the circumstances."

WISCONSIN

The Democratic National Committee and the Wisconsin Democratic party filed a lawsuit Wednesday to expand voting access for the Wisconsin primary on April 7 amid concern over the coronavirus, report CBS News associate producers Eleanor Watson and Sarah Ewall-Wice.

The lawsuit filed Wednesday by the Democratic National Committee and the Wisconsin Democratic Party seeks to expand access to voting for those who are worried about their health but want to exercise their right to vote.

The lawsuit aims to extend the election and mail-in voter registration deadline from Wednesday to April 3 and extend the deadline for absentee mail-in ballots to reach the municipal clerks' offices.

Wisconsin is the only state holding a primary on the 7th and has 84 delegates up for grabs.

CONGRESSIONAL COVERAGE

IN THE SENATE

Governor Kay Ivey in Alabama has moved the Senate Republican primary runoff between former Auburn football coach Tommy Tuberville and former AG Jeff Sessions from March 31 to July 14, reports CBS News political unit associate producer Eleanor Watson. The action comes after Alabama's Secretary of State John Merrill requested emergency opinion from the state attorney general's office on whether or not the governor can postpone the election under emergency powers. Ivey declared a state of emergency last week. In the initial primary on Super Tuesday, Tuberville won 33% of the vote, and Sessions won 32%. Since no candidate reached the 50% threshold, the top two, Tuberville and Sessions, will compete in the runoff in July to take on incumbent Democrat Senator Doug Jones in November.

IN THE HOUSE

The marquee House race last night in Illinois' 3rd saw a tight finish, though with 99% of precincts in, progressive candidate Marie Newman has officially beaten incumbent Congressman Dan Lipinski. It is a win for a progressive movement that saw losses with other House-backed candidates like Jessica Cisneros in Texas' 28th, and a 3-0 sweep for Biden in all three states on Tuesday.

"This is a critical victory for the progressive movement in showing that voters are ready for a new generation of progressive leadership in the Democratic Party," an email from Justice Democrats, which backed Newman, said.

In a call with reporters, Newman told CBS News political unit broadcast associate Aaron Navarro that while her win shows the "progressive movement is strong," she was able to win because of a wider coalition of Democratic voters. "I have been fortunate and blessed enough to be endorsed by everyone from Cory Booker, Kirsten Gillibrand, Bernie Sanders, Elizabeth Warren, Pramila Jayapal, Jan Schakowsky, AOC, Ro Khanna, every part of the party understands that my platform is in alignment with my district and alignment with the district is really the most important thing," she said.

She ousted Lipinski who has been representing southwest Chicago and its suburbs since 2004, when his father and former Congressman Bill Lipinski named him as his replacement. "I'm very proud of the work I've done and my father did before me. We can talk more about the legacy later on, but I am very proud of what I have done as a representative in the district and what my father did in the district," Lipinski said in a press conference Wednesday where he officially conceded. "We ran a good campaign against tremendous headwinds…but as the numbers stand right now it appears that I will not prevail."

In 2018, Newman lost by two points to Lipinski, a blue dog Democrat who is notably pro-life. She is going to be the likely winner in November, since a Republican hasn't held office here since 1975, and Hillary Clinton won this district by 15 points in 2016.

Another notable race result could be seen in Illinois' 14th District, which also encompasses parts of Chicago's suburbs. Dairy business owner Jim Oberweis won with 25.6% of the vote in a crowded Republican field.

"This has been a spirited and well fought campaign. I have been disappointed in the negative tone that the campaign has taken, but all of that is behind us. Now is the time for us as Republicans to come together and finish the mission which is to defeat Lauren Underwood in November," he said in a statement last night.

This district is a target for House Republicans after Democrat Congresswoman Lauren Underwood flipped the district in 2018. But Oberweis is a perennial Illinois candidate who has lost in bids for senate, governor and this same district in 2008. Other Illinois GOP results like Jeanne Ives and Illinois' 6th and particularly Mary Miller in Illinois' 15th, bode well for efforts to add more Republican women in the House. There are currently 11 active incumbent women Republicans, though Miller's nomination in a safely Republican open seat in southeast Illinois could add to the ranks. In Champaign County, the only county won by Sanders, Democrat Betsy Dirksen Londrigan easily won her primary and is set for a notable rematch with Republican Congressman Rodney Davis.