Leading Republican presidential contenders Mitt Romney and Herman Cain will have the chance to pull away from Rick Perry and the rest of the pack Wednesday in the first presidential debate with less than a year to go until next year's general election.

The ongoing string of sexual harassment allegations against Cain could weaken him in the post-debate polls if he finds himself backtracking again during the debate.

That would give Perry a chance to gain some momentum if he can show he's reengerized after several sloppy debate performances and campaign appearances.

The debate, scheduled for 5 p.m. PST and broadcast on CNBC, is focused on the American economy.

Here's five topics that could foster interesting discussions:

Taxes. The Republican candidates, minus Ron Paul, generally want to overhaul the income tax code to make wealthier Americans pay less while dropping benefits that exist for poorer Americans.

Most of the candidates have suggested that they favor a quick and aggressive rewriting of the tax code. But do they want the tax changes to be phased-in or to come as a sudden switch as soon as IRS computers are ready to handle the new math?

We know Perry and Newt Gingrich want filing an income tax return to be as easy as filling out a postcard, but candidates have very different stances on which of the few,  if any, of the deductions allowed on income should not be eliminated. One of the deductions is for homeownership, a tax break which benefits those that can of course afford homes. So what role does the government have in getting people into homes they own?

Online taxes. Calls for a flatter tax haven't seem to have been matched by talk of revolutionizing taxes to meet the 21st century economy. Where do the candidates stand on national online sales tax for both goods and services? A so-called "Amazon" tax greatly divides the business community and could further separate the Cains from the Perrys.

Healthcare. The pitch on energy from the Republican contenders is to open up more oil drilling in America, moving jobs from the green energy sector to the unrenewable sector. On healthcare, the collective party goal is to repeal President Barack Obama's prized reform law.

Undoubtedly, the law has caused healthcare-related companies to cut some jobs. But the law also has sped up the development of a health information technology sector. Repealing would likely slow that growth. How would the candidates ensure the decline is offset? In broader terms, how can the federal government increase overall employment instead of shuffling people around who already have jobs?

Infrastructure. Republicans and Democrats in Congress are making progress on legislation that would give states more flexibility in how they spend billions of dollars in federal funds for transportation infrastructure. What role should the president have in fast-tracking certain projects over others? What's the best way to find funding for infrastructure improvements, which would make more parts of the American economy attractive to investors and young intellectuals from around the globe?

Trade. Certainly, there should be many mentions of China, India and Brazil at Wednesday night's debate. Trade with those countries has a tremendous effect on individual consumer spending. How does that change in each candidate's White House?

Like reporter Paresh Dave on Facebook, follow him on Twitter, circle him on Google+ or send him an e-mail.