Republicans opened Monday night's prime-time convention with dark warnings about America's future if President Donald Trump doesn't win a second term. "The only way they can take this election away from us is if this is a rigged election," Trump told hundreds of Republican delegates gathered in North Carolina, raising anew his unsupported concerns about Americans' expected reliance on mail voting during the pandemic. Experts say mail voting has proven remarkably secure. The GOP convention marks a crucial moment for Trump, a first-term Republican president tasked with reshaping a campaign he is losing by all accounts, at least for now.