02:50 - Source: CNN
Health care at the center of tight Nevada race

The sitting Senators in two of the most closely watched re-election fights this fall are running nearly even with their challengers, according to new CNN polls conducted by SSRS.

Democratic Sen. Claire McCaskill edges challenger Josh Hawley 47% to 44% among likely voters in Republican-friendly Missouri, while Republican Sen. Dean Heller stands four points behind his Democratic challenger Jacky Rosen in Nevada (47% Rosen to 43% for Heller), which has broken for Democrats in each of the last three presidential contests and has been a regular Senate battleground in the last decade.

Related: Full poll results for Missouri and for Nevada

In both states, the political equilibrium has been shifting away from the party of the incumbent senator up for reelection this year. Missouri is one of several states where Democratic Senators are on defense in deep-red territory, a playing field that could be a bright spot for the GOP even while control of the House of Representatives is squarely in play. Nevada is widely seen as Democrats’ best Senate pickup opportunity.

President Donald Trump’s approval rating among likely voters is a mirror image in these two states, illustrating the political challenge facing each Senator. While 51% of Missouri likely voters approve of Trump’s performance, an equal 51% of Nevada likely voters disapprove of the way the President is handling his job.

Sen. Claire McCaskill is being challenged by Missouri Attorney General Josh Hawley

In Missouri, both McCaskill and Hawley have net-positive favorability ratings among those likely to vote, albeit not by large margins: 49% favorable to 46% unfavorable for McCaskill and 43% favorable to 38% unfavorable for Hawley. A sizable 19% of likely voters have yet to form an opinion about Hawley. Among the broader group of registered voters, views on McCaskill are almost evenly split, 46% unfavorable to 45% favorable, while Hawley’s numbers remain positive, 40% favorable to 34% unfavorable.

Heller is underwater in favorability in Nevada, with 44% of registered voters viewing him unfavorably vs. 40% favorably. Rosen’s numbers tilt positive, 39% favorable to 36% unfavorable, but about a quarter (26%) are unsure of how they feel about her.

About 1 in 5 likely voters who have chosen a candidate in each state say they could change their minds about the Senate race before Election Day.

Women break for the Democrat by double-digit margins in both states (55% to 38% in Missouri, 52% to 38% in Nevada), while men favor the Republican nominee in both (by 13 points in Missouri, 7 in Nevada).

Independents back the incumbent in both states, but McCaskill benefits from their support more than Heller does. Independents in Missouri break sharply in McCaskill’s favor, 50% back her and 36% Hawley Another 8% back one of the two third-party candidates who will appear on the ballot in November, 6% behind Libertarian Japheth Campbell, 2% Green Jo Crain. Nevada independents tilt toward Heller (43% to 35%) while being more likely than Missouri voters to stay away from the two major parties and choose the Libertarian candidate (10% back Tim Hagan) or the “none of these candidates” option that Nevada includes on its ballot (11%).

Health care is key

Health care tops voters’ priority list in both states, with 31% of Missouri voters calling it the most important issue in deciding their vote along with 26% saying so in Nevada. The economy ranks second in both states, 21% choose it in Missouri and 23% do so in Nevada. Nevada voters are more apt to prioritize immigration than are Missouri voters (17% in Nevada vs. 12% in Missouri).

02:33 - Source: CNN
Dean Heller sticks with Trump on health vote

Las Vegas, Nevada, was the site of one of the worst mass shootings in US history one year ago and 10% of voters in the state say gun policy is their most important issue in deciding whom to support for Senate, about the same as in other states where CNN has asked this question. Younger voters (21% of those under age 35 call it their top issue compared with 10% or less among older voters) are more apt than others to call it their top issue.

Those likely voters who say health care is their top issue break heavily for the Democrat in both states (McCaskill holds a 69% to 27% lead among that group, while Rosen tops Heller 74% to 16% among health care voters in Nevada). Voters more focused on the economy or immigration are more apt to back to the Republican in both contests.

In the Nevada gubernatorial contest, Democrat Steve Sisolak edges Republican Adam Laxalt 45% to 41%, with 5% saying they back Libertarian Jared Lord and 7% none of these candidates, an option that is included on the Nevada ballot.

The CNN Polls in Missouri and Nevada were conducted by SSRS September 25 through 29 among random statewide samples reached on landlines or cellphones by a live interviewer. In Missouri, results for the full sample of 1,003 adults have a margin of sampling error of plus or minus 3.7 percentage points, for the subset of 906 registered voters, it is plus or minus 3.9 and for the 756 likely voters plus or minus 4.3 percentage points. In Nevada, results for the full sample of 1,003 respondents have a margin of sampling error of plus or minus 3.8 percentage points. It is 4.1 for the sample of 851 registered voters and 4.6 for results among the 693 likely voters.