Nov 9 (Reuters) - The Republican presidential contenders meet on Wednesday in the ninth debate in the race for the nomination to challenge President Barack Obama in 2012.
Here are five things to watch during the debate at Oakland University in Rochester, Michigan.
HOW PROMINENT IS HERMAN CAIN'S HARASSMENT CONTROVERSY?
The debate will focus on the U.S. economy, potentially limiting the discussion of the harassment allegations against Cain by four women that threaten to derail his campaign. Cain has denied the charges.
His rivals have mostly tiptoed around the subject, trying to avoid looking like they are piling on. But even if the moderators do not broach the issue, it will be hard for voters to forget because it has been the overwhelming focus of campaign coverage for more than a week.
Polls show the controversy has eroded favorable perceptions of Cain, a former pizza executive, without knocking him from his spot near the top of the pack with Mitt Romney.
WILL ROMNEY BE A TARGET AGAIN?B
Romney, the former Massachusetts governor, has been hit hard by his rivals in the last two debates but has largely shrugged off the attacks in smooth performances that helped him retain his spot near the top of the Republican pack.
While others have bounced up and down in the polls, Romney has stayed steady near the top with support in the low to mid-20s.
But his support for abortion rights and a healthcare mandate while governor of Massachusetts -- he now opposes both -- still makes him an object of suspicion for many social and religious conservatives.
Texas Governor Rick Perry, who zoomed to the top of polls after getting in the race in August only to fall back after bad debate performances, has been particularly aggressive in challenging Romney.
The debate will be a homecoming for Romney, who was born in Michigan and whose father was a governor and auto executive in the state.
CAN GINGRICH CONTINUE TO BUILD MOMENTUM?
Former U.S. House Speaker Newt Gingrich has begun to climb slowly in the polls after a series of strong debate performances as conservatives search for a candidate to coalesce around.
A USA Today/Gallup survey on Tuesday put him in third place with 12 percent support, up 5 percentage points in a month, and other polls have shown a similar modest climb.
The challenge for Gingrich will be to continue that momentum as he begins to get more scrutiny, and to turn that support into actual votes after a slow start in campaign organizing.
MICHIGAN'S ECONOMIC TROUBLE IN THE SPOTLIGHT
The economic struggles in Michigan, which has seen its manufacturing base hit hard by the downturn, will provide the framework for a debate on economic issues.
The state unemployment rate of 11.1 percent is the third-highest in the country and well above the 9 percent national rate.
Republican opposition to bailouts for the auto industry, which helped revive General Motors and Chrysler, is sure to get scrutiny.
Democrats already have released a web video attacking Romney's opposition to the auto bailouts. They hope it will be a potent weapon in the state if Romney and Obama meet in the 2012 general election.
WILL ANY OTHER CONTENDERS RISE?
Time is running out for other longshot contenders -- former Utah Governor Jon Huntsman, U.S. Representatives Michele Bachmann and Ron Paul, and former U.S. Senator Rick Santorum -- to make an impression.
Paul is a forceful debater with a dedicated following but has not been able to break through to a broader electorate. Huntsman skipped the last debate in Nevada and is focused on making a strong showing in the early voting state of New Hampshire.
Santorum and Bachmann are working hard in Iowa, which kicks off the nominating race on Jan. 3 with the hope a strong showing there will propel them into later states with momentum. (Writing by John Whitesides; Editing by Bill Trott)