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Monmouth University Polling Institute

Trump Widens Lead Over Clinton

Thursday, September 15, 2016

Grassley holds sizable edge for Senate

West Long Branch, NJ  - Donald Trump now has an 8 point lead over Hillary Clinton in the battle for Iowa's electoral votes, according to the Monmouth University Poll .  He held a slimmer 2 point edge in July.  In the race for U.S. Senate, incumbent Chuck Grassley maintains a double digit advantage over Democratic challenger Patty Judge.

Among Iowa voters likely to participate in November's presidential election, 45% currently support Trump and 37% back Clinton.  Another 8% intend to vote for Libertarian Gary Johnson, 2% say they will support Green Party candidate Jill Stein, 2% say they will vote for another candidate, and 6% are undecided.  Trump's current standing is similar to his 44% share two months ago, but Clinton has lost support since July when she had a 42% vote share.

Among self-identified Republicans, 81% support Trump, which is down from 87% in July.  Clinton has improved her standing among Democrats from 86% two months ago to 91% in the current poll.  Trump has been able to increase his overall lead, though, by improving his share of the independent vote.  He now leads Clinton 44% to 29% among independents, compared to a much narrower 39% to 35% edge he had in July.

Nearly half (48%) of Iowa voters under age 50 currently support Trump compared to 33% for Clinton, 10% for Johnson, and 4% for Stein or another candidate.  Two months ago, the under 50 vote split 51% for Trump, 32% for Clinton, 7% for Johnson, and 3% for another candidate.  In Monmouth polls conducted nationally and in other states, Clinton has had the advantage with younger voters.

Voters age 50 and older are almost evenly divided between the two major party nominees.  Currently, Trump has the support of 42% of this group, Clinton has 41%, Johnson has 6%, and other candidates have 4%.  In July, Clinton actually had an advantage among voters age 50 and older, with 50% support compared to 38% for Trump, 4% for Johnson and 1% for other candidates.

Trump (42%) and Clinton (43%) are basically tied among voters with a college degree while Trump leads 47% to 34% among those without a college education.  In July, Clinton had a 46% to 34% edge with college graduates while Trump had a 50% to 40% lead among those without a college degree.

"Iowa is one of the few places where Trump has been able make inroads among voting blocs that generally support Clinton," said Patrick Murray, director of the independent Monmouth University Polling Institute.

Iowa voters take a dim view of both major party candidates.  Only 32% have a favorable opinion of Trump while 55% hold an unfavorable view of him, which is similar to his 33% - 51% rating in July.  Likewise, only 30% have a favorable opinion of Clinton while 58% hold an unfavorable view of her, which is similar to her 32% - 56% rating two months ago. 

Turning to the Hawkeye State's U.S. Senate race, six-term incumbent Chuck Grassley has nearly doubled his prior lead over former Lieutenant Governor Patty Judge.  The race now stands at 56% for Grassley and 39% for Judge, with 2% supporting other candidates and 3% who are undecided.  The incumbent held a 52% to 42% lead in Monmouth's July poll.

Grassley's electoral strength is built on a strong job performance rating from Iowa voters - 58% approve and 31% disapprove of the job he has done in Washington.  He also has a solid personal rating of 50% favorable and 29% unfavorable, compared with a 46% favorable and 31% unfavorable rating in July.

Voters are more divided about the challenger.  Judge holds a 27% favorable and 20% unfavorable rating with 52% having no opinion of her.  Her July rating was slightly better at 30% favorable and 14% unfavorable, with 56% having no opinion.

The Monmouth University Poll  was conducted by telephone from September 12 to 14, 2016 with 404 Iowa residents likely to vote in the November election.  This sample has a margin of error of + 4.9 percent.  The poll was conducted by the Monmouth University Polling Institute in West Long Branch, NJ.



(* Some columns may not add to 100% due to rounding.)


1/2.   If the election for President was today, would you vote for Donald Trump the Republican, Hillary Clinton the Democrat, Gary Johnson the Libertarian, or Jill Stein of the Green Party?  [ IF UNDECIDED: If you had to vote for one of the following candidates at this moment, who do you lean toward Donald Trump or Hillary Clinton?]  [ NAMES WERE ROTATED ]

45%     Donald Trump

37%     Hillary Clinton

  8%     Gary Johnson

  2%     Jill Stein

  2%     (VOL) Other candidate

  6%     (VOL) Undecided

3.      If the election for U.S. Senate was today, would you vote for Chuck Grassley the Republican, Patty Judge the Democrat, or some other candidate?  [ IF UNDECIDED : If you had to vote for one of the following candidates at this moment, who do you lean toward - Chuck Grassley or Patty Judge?]  [ NAMES WERE ROTATED ]

56%     Chuck Grassley

39%     Patty Judge

  2%     Other candidate

  3%     (VOL) Undecided

Regardless of who you may support for president…


4.      Is your general impression of Donald Trump favorable or unfavorable, or do you have no opinion of him?  

32%     Favorable

55%     Unfavorable

14%     No opinion

5.      Is your general impression of Hillary Clinton favorable or unfavorable, or do you have no opinion of her?  

30%     Favorable

58%     Unfavorable

12%     No opinion

Turning to the Senate race…


6.      Is your general impression of Chuck Grassley favorable or unfavorable, or do you have no opinion of him?  

50%     Favorable

29%     Unfavorable

21%     No opinion

7.      Is your general impression of Patty Judge favorable or unfavorable, or do you have no opinion of her?  

27%     Favorable

20%     Unfavorable

52%     No opinion

8.      Do you approve or disapprove of the job Chuck Grassley is doing as U.S. senator?

58%     Approve

31%     Disapprove

11%     (VOL) No opinion


The Monmouth University Poll  was sponsored and conducted by the Monmouth University Polling Institute from September 12 to 14, 2016 with a random sample of 404 likely Iowa voters.  Interviews were conducted by a live caller in English, including 353 drawn from a list of registered voters (203 landline / 150 cell phone) and a random digit dial supplement of 51 cell phone interviews.  Monmouth is responsible for all aspects of the survey design, data weighting and analysis. The final sample is weighted for age, gender, race and partisanship based on voter list and U.S. Census information.  Data collection support provided by Braun Research (field), Aristotle (voter list sample), and SSI (RDD sample).  For results based on this sample, one can say with 95% confidence that the error attributable to sampling has a maximum margin of plus or minus 4.9 percentage points (unadjusted for sample design).  Sampling error can be larger for sub-groups (see table below).  In addition to sampling error, one should bear in mind that question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of opinion polls.

Click on pdf file link below for full methodology and results by key demographic groups.

Download this Poll Report with all tables

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