Forecasts of thunderstorms have hindered US President Barack Obama's nomination party, forcing Democrats to move his planned acceptance speech from a 74,000-seat outdoor football stadium to a much smaller indoor venue.
The shift to the Time Warner Cable Arena was a setback for Mr Obama, who hoped to create a spectacle in the Bank of America stadium tomorrow to rival his 2008 acceptance speech.
It was also a letdown for thousands of Obama supporters who had been given tickets to the biggest speech in his campaign for the 6 November election against Republican rival Mitt Romney.
Weather forecasters predicted a chance of thunderstorms tomorrow night in Charlotte, which has been battered by heavy evening rains for the last few days.
Mr Obama and the Democrats kicked off their convention with a high-energy night yesterday that featured an impassioned speech by first lady Michelle Obama, who portrayed her husband as a man who had lived through and understood the struggles of everyday Americans.
The address fired up Democrats, who today will hear from the party's most popular elder statesman, former President Bill Clinton. He will try to build on the momentum of the first night with a reminder to voters of the economic good times he led in the White House.
Republicans were quick to put their own spin on the venue change, questioning whether Democrats were having trouble filling the seats in the stadium, home to the NFL's Carolina Panthers.
"Suddenly Team Obama is moving inside after questions about enthusiasm for the event. What's the real forecast for the speech? Forty percent chance of lies and scattered excuses," Republican National Committee spokeswoman Kirsten Kukowski said.
Obama campaign officials denied they had struggled to fill the seats, saying they could not risk the possibility of having to evacuate the open-air stadium in the event of thunderstorms.
"We're all disappointed because we had 65,000 ticket holders plus 19,000 people who were on the waiting list, ready and excited and fired up to hear the president deliver his speech," campaign spokeswoman Jen Psaki said.
"We know that Mother Nature doesn't always cooperate, unfortunately. We wish she did," she said.
Both parties have now been forced to adjust their convention programs because of weather. Tropical Storm Isaac disrupted Romney's Republican nominating convention last week in Florida, forcing him to cancel one day of the planned four-day gathering.
Mr Obama's shift to the indoor arena that holds about 20,000 people will be costly. Democrats had a $5 million budget for the stadium event. Mr Obama will speak to supporters who had tickets for the stadium on a conference call tomorrow afternoon.
Mr Obama arrived in Charlotte this afternoon, but White House officials would not say whether he would visit the convention hall for the evening session. Clinton's speech highlights a night that will conclude with Mr Obama's nomination for a second term.
"He's going to make the case for Barack Obama," Chicago Mayor Rahm Emanuel, Mr Obama's former chief of staff and a former Clinton aide, told CBS's "This Morning."
He said Mr Clinton will remind voters of "who we are as a party and why that matters to the middle class and people who are struggling." The two share the "same values, same policies, same goals," Mr Emanuel said.
Mr Clinton's high approval ratings, and voter nostalgia for the budget surpluses and job growth he produced during two terms as president in the 1990s, have made him a valuable asset despite a sometimes rocky relationship after Mr Obama's bitter 2008 primary battle with Mr Clinton's wife, former first lady Hillary Clinton.
Bill Clinton has already appeared in an ad for Mr Obama in which he argues Mr Romney would take the country back to Republican policies of deregulation and tax cuts for the rich "that got us in trouble in the first place."
Mr Obama is eager to align himself with Mr Clinton's economic successes and benefit from Mr Clinton's appeal to white working-class voters who have been slow to warm up to Mr Obama.
An online Reuters/Ipsos poll today gave Mr Romney a slight edge over Mr Obama among likely voters, 46% to 44%, barely changed from Mr Romney's 1-point advantage yesterday. The two contenders have been running close in national polls for months.
Early television viewing figures showed the audience for the first lady's address was about 11.1 million on the three US free-to-air networks. That was in line with those who tuned in last week to hear Ann Romney speak about her husband, Mitt.
In social media, reaction to Michelle Obama's speech was off the charts.
She racked up 28,000 tweets per minute at the conclusion of her speech, according to Twitter. That was double the 14,000 that Mr Romney saw in his convention speech last week. Ann Romney's tweets per minute tally was just over 6,000.
