Gallup sees President Obama strong on approval rating even though Rasmussen doesn't, and the Indiana Senate race is tight. Here's our guide to today's polls and why they matter. 

Findings: Obama's approval rating has been at or over 50 percent in Gallup Daily tracking and is therefore getting back to post-convention levels, when Obama got a bump. That said, the Republican-leaning Rasmussen finds Obama with a negative job approval rating.
Pollster: Gallup, Rasmussen
Methodology: Both organizations' tracking. 
Why it matters: Gallup explains that in the past month Obama's approval ratings have ranged from 43 percent to 52 percent, "levels historically associated with either near-certain defeat or near-certain re-election for an incumbent. Obama is currently at the high end of that range, and has had more good days than bad this month..." 
Caveat: Obama's numbers have fluctuated a lot, and of course there's Rasmussen's numbers. 


Findings: Democrat Joe Donnelly is up by a slim margin in Indiana against Republican Richard Mourdock in Indiana's Senate race.
Pollster: Howey/DePauw
Methodology: Poll of 800 likely voters September 19, 20 and 23 with a margin of error of +/-3.5 percent.
Why it matters: Though Romney has a hold on the presidential race in the state, the Senate race is way more up for grabs. Mourdock is one of the Tea Party conservatives who ousted a Republican moderate, in this case, long-serving Sen. Dick Lugar. Brian A. Howey explains that Indiana Republicans "took a historic gamble" in the primary in picking Mourdock, who "galvanized a Tea Party base and GOP dissatisfaction over Lugar's age and longevity to forge a historic upset." 
Caveat: There just haven't been enough polls. "Ultimately, we believe the Republican candidates have a clearer path to a plurality in these races than do the Democrats. But there just isn’t enough information to justify rating either Indiana or North Dakota as leaning Republican anymore," the University of Virginia's Larry J. Sabato, Kyle Kondik, and Geoffrey Skelley explain.