MILWAUKEE — A new Marquette Law School Poll finds Democratic candidate Hillary Clinton with support from 46 percent of Wisconsin registered voters and Republican candidate Donald Trump with support from 36 percent in a head-to-head presidential matchup. Sixteen percent say they will vote for neither candidate, will not vote, or don’t know how they will vote.

In the most recent Marquette Law School Poll, in July, Clinton had 43 percent support and Trump 37 percent, with 18 percent saying they would vote for neither, would not vote or didn’t know.

Among likely voters, i.e., those who say they are certain they will vote in November, Clinton is supported by 52 percent and Trump by 37 percent in the new poll, with 10 percent saying they will support neither candidate. In July, likely voters gave Clinton 45 percent support, Trump 41 percent and 14 percent said they would vote for neither.

In a four-way matchup including Clinton, Trump, Libertarian candidate Gary Johnson and Green Party candidate Jill Stein, Clinton is supported by 42 percent of registered voters, with Trump at 33 percent, Johnson at 10 and Stein at 4. A total of 11 percent in that matchup say they will vote for none of the candidates, won’t vote or don’t know how they will vote. Among likely voters, Clinton receives 47 percent, Trump 34, Johnson 9 and Stein 3. In July’s four-candidate question among registered voters, Clinton received 40 percent, Trump 33, Johnson 10 and Stein 4. Among likely voters in that poll, Clinton received 43 percent, Trump 37, Johnson 8 and Stein 2 percent.

In a head-to-head matchup for Wisconsin’s U.S. Senate race, among registered voters, Democratic candidate Russ Feingold is supported by 49 percent while Republican incumbent Ron Johnson receives 43 percent. In July, Feingold had 48 percent support and Johnson 41 percent.

Among likely voters in November’s election, Feingold has the support of 53 percent while Johnson is supported by 42 percent. Among likely voters in July, Feingold was supported by 49 percent and Johnson by 44 percent.

When Libertarian candidate Phil Anderson is included in the Senate contest, among registered voters, Feingold receives 47 percent, Johnson 38 percent and Anderson 7 percent. Among likely voters, it is Feingold 50 percent, Johnson 39 percent and Anderson 7 percent.

For registered voters in the July poll, Feingold received 45 percent, Johnson 38 percent and Anderson 8 percent. Among likely voters, Feingold received 46 percent, Johnson 40 percent and Anderson 7 percent.

Among Republicans and independents who lean Republican, 78 percent say they are absolutely certain they will vote in November compared to 80 percent in the July poll. Among Democrats and independents who lean Democratic, certainty of voting rose from 78 percent in July to 81 percent in August.

The poll was conducted August 4-7, 2016. The full sample includes 805 registered voters interviewed by cell phone or landline, with a margin of error of +/- 4.6 percentage points. Results for likely voters are based on 683 respondents, with a margin of error of +/- 5.0 percentage points.