AP

CHARLOTTE DEMOCRATS open their national convention on Tuesday offering President Barack Obama as America’s best chance to revive the ragged US economy and asking voters to be patient with incomplete results so far.

Michelle Obama, in her opening- night speech, aims to give people a very personal reminder of “the man that he was before he was president.” “The truth is that he has grown so much, but in terms of his core character and value, that has not been changed at all,” Michelle Obama said in interview airing on SiriusXM’s “The Joe Madison Show.”

The three-day convention has drawn thousands of delegates to a state Obama narrowly carried in 2008. And although Obama no longer is the fresh-faced newbie who leveraged a short Senate career into an audacious run for the nation’s highest office, he still can excite partisans, and Democrats were counting on massive numbers to pack a stadium for his speech later in the week.

Virginia Senator Mark Warner and a host of Democratic allies worked to rev up delegate enthusiasm, saying Obama has a strong record to defend. They noted the president had helped the economy rebound, presided over an increase in the stock market and brought troops home from Iraq and Afghanistan.

“We’ve got some truth telling to do,” Warner told Florida delegates at a breakfast meeting. “America is better off today than it was four years ago when this president took over.”

Newark, New Jersey, Mayor Cory Booker told the delegates Democrats need to get fully behind Obama, comparing the differences between a large voter turnout in his home state during the 2008 election and a more modest outpouring one year later, when his home state elected Republican Chris Christie as governor.

“Change is never made in a sedentary position,” he said.

The Democrats dispatched US Senate candidate Elizabeth Warren, who hopes to unseat Republican Scott Brown in Massachusetts, to make the case for Obama on morning talk shows, and she acknowledged that “it’s tough out there” for many Americans.

New government reports out on Tuesday underscored that reality.

US factory activity shrank for the third straight month in August and construction spending fell in July from June by the largest amount in a year. Next up: The Labour Department will release new jobs numbers on Friday.

Economists expect to see some job gains but believe the unemployment rate will remain at 8.3 percent.

Democrats released a party platform for ratification on Tuesday that echoes Obama’s call for higher taxes on the wealthy and reflects his shift on gay marriage by supporting it explicitly.

The president rallies in Virginia on Tuesday before joining the convention a day later.