New Iowa poll: Clinton, Trump close; Grassley leading

For the second time in two days, a poll of Iowa voters says the state is a tossup with less than five months to go before Election Day.

A Wall Street Journal/NBC News/Marist poll, released Wednesday, says that Democrat Hillary Clinton leads Republican Donald Trump by a three-point margin, 42 percent to 39 percent.

The poll, which sampled the opinions of registered voters in the state, also said U.S. Sen. Chuck Grassley, R-Iowa, holds a 10-point lead over Democratic challenger Patty Judge. A Monmouth University Poll released on Tuesday reported the same margin. That poll asked questions of likely voters.

Iowa has traditionally been a battleground state in presidential elections, and with the exception of a poll in June that said Clinton led Trump by double digits, the other more recent surveys in the state have portrayed a close contest.

Like other polls across the country, the Journal/NBC News/Marist poll said Clinton and Trump are seen unfavorably by a large part of the Iowa electorate. But unlike many other polls, this survey said they are running fairly even in that department. In most other polls, Trump is seen unfavorably by a larger share of poll respondents.

Both Clinton and Trump were seen unfavorably by 61 percent of the respondents, according to the Journal/NBC News/Marist poll. A slightly higher share of Iowans see Clinton favorably, as opposed to Trump, 34 percent to 31 percent.

The poll sampled the opinions of 822 registered Iowa voters from July 5-10. It has a margin of error of plus or minus 3.4 percentage points.