CHARLOTTE, N.C. - President Donald Trump warned Republicans who officially backed his bid for a second term on Monday that November’s election could be “rigged” despite offering no evidence, as the party began outlining its vision for the future on the first night of its national convention. Trump spoke on the first day of the sharply scaled-back Republican National Convention in Charlotte, North Carolina, after receiving enough votes to win the nomination to take on his Democratic rival, former Vice President Joe Biden, in the Nov. 3 election. The president repeated his assertion that voting by mail, a long-standing feature of American elections that is expected to be far more common during the coronavirus pandemic, will lead to widespread fraud. Independent election security experts say voter fraud is extraordinarily rare in the United States. “The only way they can take this election away from us is if this is a rigged election,” Trump said. “We’re going to win.” The four-day conve