Senior Democratic strategists, fearful of alienating President Trump’s working-class base, are planning a midterm advertising strategy that targets House Speaker Paul Ryan, R-Wis.

This emerging strategy to win back the House in 2018, boosted by Ryan's tumbling national approval ratings, is a quiet concession by the Democratic Congressional Campaign Committee that attacking Trump could turn off white voters in targeted districts who are unhappy with Washington and open to voting for the party's candidates, but remain loyal to Trump or are not ready give up on him.

“There is no interest in isolating these voters,” said a party insider familiar with the approach of the Democrats' House campaign arm.

The party needs to gain a net of 24 seats this time next year to win a majority in the House. Historic trends, Trump’s low national approval ratings plus the national generic ballot asking voters which party they want to control Congress, all suggest Democrats have an opportunity to succeed.

But the Republicans also hold some structural advantages. Trump’s numbers are holding steady in Republican districts, many gerrymandered enough to withstand any political headwinds, and GOP voters are more likely to show up in midterms than are Democrats. House Minority Leader Nancy Pelosi, D-Calif., also continues to be a political problem for Democratic candidates in competitive districts.

To achieve an advantage heading into the midterm, the DCCC is using this year’s off-year elections, including Tuesday’s gubernatorial and down-ballot contests in New Jersey and Virginia, to try out campaign themes tailored to specific, sought-after voting blocs, to see what might work.

“The DCCC is utilizing statewide and local races in Virginia, New Jersey, and California in order to test which messages best motivate African American and Hispanic voters, as well as likely Democratic base voters more broadly,” a committee official said. “The message buckets include voter education, promotion of key Democratic values and using Republicans in Washington as a motivator.”

In many districts across the country targeted by the Democrats, that will include advertising highly critical of Trump, tying Republicans to his provocative rhetoric and in some instances, controversial agenda.

But armed with polling data and information gleaned from focus groups, the DCCC sees opportunities for gains in predominantly white districts that retain a fondness for Trump, or at least, are being patient with him — and that are deeply dissatisfied with the GOP establishment in Congress.

The Democrats view these seats, such as Northern Michigan’s 1st District; Eastern Iowa’s 1st District and Maine’s 2nd District, as crucial to reclaiming a durable House majority. Historically Democratic, they recently shifted toward the Republicans, first in their votes for Congress and then, particularly last year, for president.

Ryan’s job approval, at 31 percent nationally according to a September Washington Post/ABC News poll, has taken a hit in these territories with grassroots conservatives and Trump’s base since the first half of the year, with a perceived lack of legislative productivity, and criticism from insurgents in Washington, and sometimes, the president, damaging his image.

With that development, Democrats see an opening to drive a wedge between recently reliable Republican voters and GOP congressional candidates, without criticizing Trump’s leadership and running the risk of offending them.

Insisting to these voters that Trump is a failure, or, as some Democrats charge, a bigot, is the surest way to alienate them. "Trump matters, but how Ryan is doing is important," the Democratic insider said.