US president Barack Obama told supporters on a conference call today that his address tonight at the Democratic National Convention will outline the "stakes in this election," and that he can not wait to share his "vision for the future".
The call was held for tens of thousands of people who won't be able to see the address live after organisers, citing the possibility of thunderstorms, moved the event indoors to a smaller venue in Charlotte, North Carolina.
Mr Obama had planned to speak at the outdoor Bank of America Stadium, which seats almost 74,000 people.
Instead, he will stand at the podium at the Time Warner Cable Arena, where the convention has been held the past two days. Mr Obama delivered his 2008 acceptance at an outdoor stadium in Denver.
The president said he wanted to tell those who had planned to be in the stadium how much he regrets they couldn't all assemble in one place. He said that given the potential for lightning, it was too risky to hold the event outdoors because it would have been difficult to get everyone out quickly if needed.
"There's plenty of enthusiasm out there," he said. "We can't let a little thunder and lightning get us down."
Mr Obama said that his party's convention has been an "unbelieveable" success so far.
"This is still going to be a really close election," he said. "I really need your help, guys."
Mr Obama's campaign manager said on the call there would have been no problem filling the outdoor stadium. "It would have been standing-room only," the aide, Jim Messina, said.
The president spent the morning at his hotel preparing for his prime-time nomination acceptance speech, one aimed at convincing voters struggling in a slow economic recovery that things will get better if they give him a second term.
The speech is scheduled for shortly after 10pm local time (3am Irish time).
A Reuters/Ipsos poll found today that Mr Obama has not received much of a bounce yet in popular support from the Democratic National Convention.
The latest daily tracking poll found Republican Mitt Romney still clinging to a narrow lead of 45 per cent to Mr Obama's 44 per cent among likely voters.
Mr Romney had led by 46 per cent to 44 per cent in yesterday's poll.
Bloomberg