* Politico…

Hillary Clinton is trouncing Donald Trump in several swing House districts, Democratic Party officials say in a new memo obtained by POLITICO that touts the party’s down-ballot prospects in November but does not predict they’ll capture the chamber.

Clinton is posting double-digit leads in several vulnerable Republican districts including Rep. Bob Dold in Illinois, Florida Rep. Carlos Curbelo, California freshman Rep. Steve Knight, Rep. Mike Coffman in Colorado and Rep. Erik Paulsen in Minnesota, the Democratic Congressional Campaign Committee memo states. [Emphasis added.]

* From the memo, with emphasis added…

Problem #3: Top of the Ticket Performance Dictates the Outcome of House Races

A “congressional firewall” argument from national Republicans cannot reverse this trend

Down-ballot races are always driven by the presidential race, with performance in House races closely tied to presidential performance. With the country getting more polarized overall, this trend only increases. As Dave Wasserman notes, “Today, rates of split-ticket voting are at all-time lows and House candidates are defined by their party and the top of the ticket more than ever.”

For example, in 2008 and 2012, the national average difference in support between the top of the ticket and the House was only 1.9%. In 2014, 93% of the outcomes in House races followed the 2012 presidential result.

The 2016 election is a nationalized race defined by Donald Trump, and the national polls have Clinton in a clear lead […]

Recent DCCC polling shows that this reality is also playing out in the swing districts:

In CA-10: Hillary Clinton is beating Donald Trump by 6 points
In CA-25: Hillary Clinton is beating Donald Trump by 12 points
In CO-06: Hillary Clinton is beating Donald Trump by 14 points
In FL-07: Hillary Clinton is beating Donald Trump by 14 points
In FL-26: Hillary Clinton is beating Donald Trump by 24 points
In IL-10: Hillary Clinton is beating Donald Trump by 31 points
In MN-03: Hillary Clinton is beating Donald Trump by 24 points

Donald Trump’s likely defeat in many swing districts will be a devastating anchor that drags down House Republicans all across the country.

* The DCCC sent me its polling memo for the 10th District…

• Brad Schneider is beating Bob Dold (46% Schneider / 40% Dold)—and he has more room to grow. Schneider has a name ID deficit (64% name ID for Schneider / 77% for Dold), and voters who can identify both candidates give Schneider an even larger 18-point lead (54% Schneider / 36% Dold). So Schneider’s lead could very well expand as people get reacquainted with the candidates.

o One of Schneider’s best groups is voters under 35 years old (52% Schneider / 33% Dold) who are more likely to turn out in a Presidential election than a midterm.

• This district is rejecting Donald Trump and the Republican brand. Hillary Clinton holds a 31-point lead in a race for President (56% Clinton / 25% Trump). Voters overwhelmingly dislike Trump (22% favorable / 74% unfavorable), including 64% of
voters who have a very unfavorable view of Trump.

o Even more importantly, voters say they are more likely to vote Democratic than Republican for Congress in an unnamed matchup for Congress (49% Democrat / 31% Republican).
o Voters who are currently undecided in the vote for Congress lean Democratic by almost 2:1 before they hear candidate names (37% Democrat / 19% Republican), making them likely to break for Schneider.
o Barack Obama is also very popular in the district (63% favorable / 35% unfavorable), and voters think he is doing a good job as President (67% positive / 32% negative).

* Methodology…

This analysis is based off of a survey of n=400 November 2016 voters in IL CD-10, conducted via cellphone and landline telephone August 2-4, 2016. The data was weighted to be representative of past voter turnout. The margin of sampling error for the overall sample is +4.9% at the 95% confidence level, and it is higher for subgroups.