The order means Wisconsin's gay marriage ban remains in place as long as appeals are in place.
In August, 24% of respondents were undecided or didn't know who they would vote for. This month that was down to 20%.
The Marquette University Law School poll released Wednesday shows Walker and Burke are about even among both registered and likely voters.
Hundreds of gay couples married before a judge put her ruling overturning the state's gay marriage ban on hold pending appeals a week later.
Burke is scheduled to speak Thursday at the DNC's Women's Leadership Forum, a private event.
The Wisconsin-based retailer plans to hire about 67,000 seasonal workers, up from about 50,000 last year.
Wisconsin and Michigan are among the states affected.
The New Jersey governor plans to come on Sept. 29.
The ACLU and the Advancement Project are challenging the law.
The complaint argues that the forms are confusing.