- In Iowa, Grassley is leading Patty Judge, 51% to 42%, respectively
- In Colorado, Bennet is leading 54% to 38% over his challenger Darryl Glenn
In the Quinnipiac University swing state polls, Republican Sen. Chuck Grassley and Democratic Sen. Michael Bennet are both leading in the polls against their competitors.
In Iowa, six-term incumbent Grassley tops Democratic challenger and former Lt Gov. Patty Judge, 51% to 42%.
The percentages haven't changed much
from an NBC News/Wall Street Journal/Marist poll from July that showed that Grassley leading Judge by 10 points among registered voters, 52% to 42%.
And similarly in Colorado, the first-term senator Bennet is leading 54% to 38% over his challenger, El Paso County Commissioner Darryl Glenn.
Control for the Senate is up for grabs, with Republicans hoping to maintain their majority but facing an uphill battle by having to hold seats in blue-leaning state.
Democratic presidential nominee Hillary Clinton currently holds leads in both Iowa and Colorado, according to the latest Quinnipiac University poll
, released Wednesday. Clinton leads Donald Trump 47% to 44% in Iowa and 49% to 39% in Colorado.
The Colorado poll surveyed 830 likely Colorado voters between August 9-16 with a margin of error of plus or minus 3.4 percentage points.
The Iowa poll surveyed 846 likely Iowa voters during the same period with a margin of error of plus or minus 3.4 percentage points.