The Republican presidential candidates are expected to enter attack mode on the campaign trail today and during tonight’s CNN debate, and Democrats plan to get in on the action, too.

Florida Rep. Debbie Wasserman Schultz, who also chairs the Democratic National Committee, plans to arrive in Charleston today to ask her own questions about the GOP candidates, such as why frontrunner and former Massachusetts Gov. Mitt Romney has not released his tax returns.

The DNC released a memo questioning whether Romney has not released his returns because they might show he has paid a low tax rate.

Wasserman Schultz plans to hold a press conference at 3 this afternoon along with former DNC Chair Don Fowler and state Rep. Bakari Sellers, D-Denmark. She also will be giving local and national televised interviews before and after tonight’s debate, which runs from 8-10 p.m.

Meanwhile, comedian Stephen Colbert also is entering the political fray leading up to the Republicans’ Saturday presidential primary. Colbert announced on his program Wednesday evening that he will appear at 1 p.m. Friday at the College of Charleston’s Cistern Yard.

Colbert’s super PAC, “Making a Better Tomorrow, Tomorrow,” has a spoof message urging voters to support Georgia restauranteur Herman Cain, who dropped out of the GOP race but whose name still will appear on Saturday’s ballots. Cain is expected to address the Southern Republican Leadership Conference this afternoon and possibly endorse one of the five Republicans who remain in the race.

Meanwhile, another GOP candidate who has left the race but whose name also will be on Saturday's ballot -- Minnesota Rep. Michele Bachmann -- said today she has not yet decided who she will endorse but that she has ruled one candidate out.

Bachmann said former Speaker Newt Gingrich would be a "less than acceptable" GOP nominee, in part because he lacks "moral fiber."