Grassley has been perennially popular in his home state, where he's built a reputation as a GOP senator with an independent streak.
But a poll this week conducted by a Democratic-leaning firm for the Constitutional Responsibility Project found Grassley leading Democratic challenger Patty Judge just 48 percent to 41 percent.
It’s a margin far below Grassley’s past elections, when he’s frequently won at least 60 percent of the vote.
Wednesday, June 22, 2016
In Iowa, Patty Judge's ads are nailing Chuck Grassley to the wall and Donald Trump is the hammer
From The Hill: