Very, very large. As Wisconsin Reporter points out, the "short attention span syndrome" that has become the hallmark of extended presidential campaigns is non existent here. This campaign will last less than 30 days from now. Barrett, realizing the true purpose of the recall isn't resonating with even Democrat voters, is now making this about jobs.
That means Thursday's report will be critical because it will likely form the voters' lasting perception of Wisconsin's job picture before the vote. That report can be read several ways, and only one would be really good news to Scott Walker:
A) a great jobs report: Barrett would have to desperately spin this. He's building his campaign around Walker as having failed on jobs. If the report is spectacular, about all he has is to say that it's still not the 250,000 jobs Walker promised. I don't think that clicks with voters
B) a really bad report: no explanation needed as to who this benefits.
C) mildly improved: this would mostly benefit Barrett, much the way mildly improving job numbers on the national level aren't helping President Obama
D) Not as good as (B) for Barrett, but still very good...he can extend the existing narrative.
No matter how you slice it, Thursday is a very important day.