Democrats now lead Republicans by 52% to 41% in a nationwide generic Congressional ballot according to a new CNN poll conducted by SSRS and released Tuesday. The blue lead has increased slightly from eight percentage points in June of this year to an 11 percentage point difference in the most recent poll.

Despite Democrats' advantage on that measure, a plurality (48%) in the same poll believe Republicans will maintain control of Congress after the election, compared with 40% who believe Democrats will gain control.

Among those who favor the Democratic candidate in their district, 64% say they think Democrats will ultimately win control of Congress, while among those backing Republican candidates, 83% think the GOP will maintain control.

Compared to previous elections, 68% of registered voters say they're more enthusiastic to vote in this election than in the past. Registered Democrats and Republicans report being more excited to vote at similar levels, with 70% and 68% saying so, respectively.

However, Democrats have taken a much higher leap in enthusiasm vs. 2016 than Republicans. When CNN last asked the question, in September 2016, only 38% of Democrats said they were "more enthusiastic," while 48% of Republicans said the same. Registered Democrats jumped 32-points since 2016 and Republicans moved 20-points.

Health care is key

Health care tops the list of important issues voters will consider this fall with 81% saying it's extremely or very important to their vote for Congress, followed very closely by the economy (80%).

Immigration is on the rise as a critical issue -- from 38% in May to 44% now. However, the issue's overall importance hasn't increased substantially.

Gun policy remains a deeply important issue for almost three quarters of Americans (73% call it extremely or very important to their vote), and corruption -- an issue newly in the spotlight following Rep. Chris Collins' arrest on insider trading charges -- outpaces trade policy and taxes in importance to voters (74% call corruption extremely or very important vs. 64% on trade policy and 71% on taxes).

Beyond those issues, Trump and House Minority Leader Nancy Pelosi -- two politicians who are the subject of many a campaign ad this cycle -- provoke very different reactions. Most voters, 68%, say that Trump will be an important factor in their vote this fall, while only about a third (34%) feel the same way about Pelosi.

The Russia factor

The investigation into Russian interference in the 2016 election is climbing as a relevant issue for voters, the percentage calling it at least very important has increased by five points since May.

That rising concern comes as a majority of Americans see foreign interference as likely in this fall's elections. Six-in-ten say it's very or somewhat likely that a foreign government will interfere in the US elections this fall with only 37% saying it's not too likely or not likely at all. There are sharp differences by party on this question, with 35% of Republicans seeing foreign meddling with US congressional elections as likely, well below expectations among Democrats (83% likely) or independents (56% likely).

If a foreign government were to meddle in US elections, almost three-quarters say it would be a crisis or major problem. Almost three in 10, 28%, think it would be a crisis, 46% a major problem, 16% a minor problem, and 8% believe it wouldn't be a problem at all.

A plurality of every single demographic group viewed hypothetical meddling by a foreign government in US elections as a major problem, including those who approve of President Trump's job performance at 43%.

Those most likely to view hypothetical foreign meddling in US elections as a crisis are those who disapprove of Trump (42%), Democrats (41%), and women (36%).

Most don't know about QAnon

The group QAnon, which has become a regular presence at Trump's rallies in recent weeks, hasn't made an impression on most Americans. About two-thirds (65%) say they haven't heard anything at all about it, and another 19% have heard of it but don't know enough to have an opinion on it. The impressions it has made are largely negative: 12% say they have a negative impression of the group vs. just 2% who hold it in a positive light.

College graduates and Democrats are the most likely to have heard a great deal or just some about QAnon, but no demographic subgroup had a positive impression of them.

The CNN poll was conducted by SSRS August 9-12 among a random national sample of 1,002 adults and 921 registered voters reached on landlines or cellphones by a live interviewer. Results for the full sample have a margin of sampling error of plus or minus 3.9 percentage points, it is larger for subgroups.