Republican job-growth ideas simply \"retread\" worn policies that hurt the middle class, U.S. President Barack Obama said as his party\'s convention was to start. \"When Governor Romney had his chance to let you in on the secret sauce of job creation, he did not offer you a single new idea,\" Obama told autoworkers in Toledo, Ohio. \"It was just a retread of the same old policies that have been sticking it to the middle class for years.\" Obama said his policies, including billions in federal aid to the auto industry that Republican nominee Romney opposed, helped the industry bounce back. Romney running mate Paul Ryan said in Greenville, N.C., \"The president can say a lot of things, but he can\'t tell you you are better off\" -- a comment Vice President Joe Biden quickly responded to. \"Folks, let me make something clear,\" Biden told a Detroit union audience. \"I\'ll say it to the press. America is better off today than they left us,\" referring to the George W. Bush administration. Biden and his wife, Jill, were expected to travel to Charlotte, N.C., for the Democratic National Convention\'s opening day Tuesday. \"Putting Americans back to work\" is the No. 1 item on the party platform. Other parts of the 19-item platform -- a list of actions the party supports -- include \"asking all to pay their fair share,\" Wall Street reform, \"protecting rights and freedoms,\" defeating al-Qaida and \"maintaining the strongest military in the world.\" Two prime-time speakers Tuesday were to be first lady Michelle Obama and a keynote address by San Antonio Mayor Julian Castro, the schedule indicates. Castro was expected to emphasize the importance of investing in education, The Wall Street Journal said. Former President Bill Clinton, speaking Wednesday, is to argue Democratic policies like those he and Obama embrace led to economic expansion when he was president, the Journal said. Attending the convention are 5,556 delegates and 407 alternates, convention information indicates. Fifty percent of delegates are women and 27 percent are black, Democratic National Committee Secretary Alice Germond told USA Today. The oldest delegate is 98-year-old Mississippian Elzena Johnson. The youngest is 17-year-old Iowan Samuel Gray.