Democrat Sinema leads Republican McSally in fight for key Senate seat in Arizona: NBC News/Marist poll

Key Points
  • Democratic Rep. Kyrsten Sinema leads Republican Rep. Martha McSally in the Arizona Senate race, according to an NBC News/Marist poll.
  • The contest offers Democrats one of their best opportunities to pick up a seat in the Senate, where Republicans hold a 51-49 majority.
Rep. Kyrsten Sinema (D-AZ)
Chip Somodevilla | Getty Images News | Getty Images

Democrat Kyrsten Sinema leads Republican Martha McSally in the Arizona Senate race, one of the nation's most important contests in next week's midterm elections, a new poll found.

In a head-to-head contest, the Democratic representative garners support from 50 percent of registered voters compared with 44 percent for the GOP House member, according to the NBC News/Marist poll released Tuesday. When the poll includes Green Party candidate Angela Green, Sinema's lead over McSally tightens to 3 percentage points.

Among likely voters, 44 percent have already cast ballots in the state, where early voting is prevalent. Sinema leads among those voters — 51 percent to 47 percent.

The NBC/Marist survey has a plus-or-minus 5.4 percentage point margin of error for the likely voter sample. The race appears to be a toss-up with a week to go, according to a RealClearPolitics average of recent polls.

Democrats have one of their two best opportunities to flip a Senate seat in Arizona as Republican Sen. Jeff Flake retires in January. If McSally can hold the line for the GOP, the party's chances of keeping or expanding its 51-49 seat majority greatly improve. Senate composition has huge stakes not only for President Donald Trump's economic policy agenda, but also his sustained push to fill the federal courts with conservative judges.

What midterms will mean for the US economy
What midterms will mean for the US economy

Sinema, 42, has tried to run a centrist campaign in a state the president won by about 4 percentage points in 2016. She has extended olive branches to Republicans and voted in September to make individual tax cuts passed by the GOP last year permanent. The representative has recently faced a barrage of Republican attacks for past comments that opponents say show she is too liberal for the state.

McSally, 52, has pivoted to running a campaign with broader appeal after tying herself more closely to Trump during a three-way GOP primary. The representative and many of her Republican colleagues around the country have faced pressure for votes to repeal and replace the Affordable Care Act as Democrats make health care their signature midterm issue.

Sinema tweet

Sinema leads among Latino voters, independents and women. McSally has an edge among white voters and men.

An association with Trump may have helped McSally in a GOP primary, but it carries its risks statewide. Forty-four percent of likely voters approve of the job the president is doing, while 49 percent disapprove. Thirty-two percent say they strongly approve of Trump compared to 40 percent who strongly disapprove.

The fight over Supreme Court Justice Brett Kavanaugh's confirmation, which Republicans believe galvanized their base in key states with Senate elections, may not have much of an effect in Arizona. Only 35 percent of likely voters said they are more likely to back a candidate who supported the judge's confirmation, while 37 percent answered that they are less likely. Twenty-six percent said the confirmation fight does not make a difference in their vote.

The GOP-held Senate confirmed Kavanaugh to the top U.S. court earlier this month amid sexual misconduct accusations against him. He vehemently denied the claims. McSally said she would have supported Kavanaugh, while Sinema said she would have opposed him.

Voters in Arizona also narrowly favor Democrats in the overall fight for Congress. Forty-seven percent of likely voters said they would rather see the party control the legislative branch after November, while 46 percent said they prefer a Republican majority.

Forty-eight percent also responded that they would more likely vote for a Democrat in their district next Tuesday, while 47 percent are more likely to support a GOP candidate.

The live-caller NBC/Marist poll was conducted October 23-27 of 910 Arizona adults (which has a margin of error of plus-minus 4.1 percentage points), 793 registered voters (plus-minus 4.4 percentage points) and 506 likely voters (plus-minus 5.4 percentage points).