The U.S. Capitol dome.

An Emerson College Polling survey released Wednesday showed U.S. Sen. Richard Blumenthal with a 13 percentage point lead over Leora Levy, the winner of a Republican primary in August after her endorsement by Donald J. Trump.

The survey of 1,000 likely voters conducted from Sept. 7 to 9 for WTNH and The Hill found Blumenthal, a two-term Democrat, leading Levy 49% to 36%, with 10.5% undecided and 5% preferring someone else.

With Levy unknown to many voters and Blumenthal a household name, there is both potential for the Republican to make gains — and for the Democrat to define her to the electorate as a Trump loyalist, a liability in blue Connecticut.

The candidates offer voters stark choices on abortion, gun control and funding for climate change. Blumenthal is a long-time supporter of reproductive rights, while Levy is a late-in-life convert to the anti-abortion movement.

So far, Blumenthal’s campaign is far better financed, and a super PAC organized to support Levy with attacks on the senator has yet to show signs of attracting national Republican donors as the GOP struggles to recapture the divided Senate.

The 76-year-old Blumenthal has the advantage of 99.8% name recognition after 32 years in statewide office — a dozen in the U.S. Senate and two decades as a state attorney general who fashioned himself as a media-savvy consumer advocate.

Fifteen percent of those polled had never heard of Levy, 65, a Republican National Committee member and GOP fundraiser on the ballot for the first time, and another 19% were unsure when asked if they had a favorable or unfavorable opinion.

Overall, Blumenthal’s favorable/unfavorable split was 53% to 43%, compared to 38% to 29% for Levy. Only 5% were unsure of their opinion of the senator.

But among those most passionate — labeled as “very favorable” or “very unfavorable” — voters had mixed opinions of both candidates. Blumenthal’s advantage among those voters was just 36% to 34%. Levy had strong favorable marks from only 19%, while 22% were strongly unfavorable.

Levy is trying to become the first woman elected to the U.S. Senate from Connecticut, but Blumenthal has a 29-point lead among women.

While the candidates are split on abortion, only 7% of both male and female respondents identified the issue as “most important” in determining their vote. The economy was named most important by 40%, followed by 15% concerned by “threats to democracy.”

Emerson’s previous poll for WTNH was conducted after Themis Klarides won the endorsement of the GOP convention in May and faced a primary with Levy and Peter Lumaj. It showed Blumenthal with a 10-point lead over Klarides and a 16-point cushion over Levy.

Blumenthal won by 55% to 43% in his first race for the Senate, defeating Republican Linda McMahon, who spent a record $50 million on her campaign. He was reelected in 2016 with a 63% to 35% win over a poorly financed Dan Carter.

Emerson collects its data using automated questions to likely voters on landlines and cell phones, plus an online panel.

The margin of error in the Emerson survey is plus or minus 3 percentage points.

Emerson gets an accuracy grade of A- from the political data site, The grades are based on how closely polls conducted within 21 days of an election came to the actual results.

In 2018, Emerson was off by just two-tenths of a point in calling the 20-point victory margin of U.S. Sen. Chris Murphy’s reelection to his second term.

Mark is the Capitol Bureau Chief and a co-founder of CT Mirror. He is a frequent contributor to WNPR, a former state politics writer for The Hartford Courant and Journal Inquirer, and contributor for The New York Times.