Rep. Bruce BraleyBruce BraleyOPINION | Tax reform, not Trump-McConnell feuds, will make 2018 a win for GOP Ten years later, House Dems reunite and look forward Trump: Ernst wanted 'more seasoning' before entertaining VP offer MORE (D-Iowa) has a narrow lead over Iowa state Sen. Joni ErnstJoni Kay ErnstOvernight Finance: McConnell, Schumer spar over debt limit | WH says tax reform depends on Dems | Mnuchin doubts Trump’s corporate tax goal possible | Dem wants criminal probe of Equifax stock sales | Mystery surrounds Cordray’s plans GOP senator calls for caps on ex-presidents' benefits Senate approves Trump's debt deal with Democrats MORE (R), according to a new poll from Quinnipiac University.

Braley leads Ernst by 44 percent-40 percent in the live-caller poll in the hotly contested race.

That's a bump for Ernst since the last time Quinnipiac polled in March, when she was just starting to gain traction in the primary and before his "farmer from Iowa" comments surfaced.

Two other polls conducted immediately after the primary, one by a nonpartisan pollster and one by a Republican, found her with narrow leads. But those might have been picking up on post-primary enthusiasm for Ernst.

The live-caller poll of 1,277 registered voters was conducted on landlines and cellphones from June 12-16 and has a margin of error of plus or minus 2.7 percentage points.