A majority of respondents in a new NBC/Wall Street Journal poll of registered voters said Democratic congressional candidates are out of step with most Americans.

Asked whether Democratic candidates' approaches to the issues "are generally in the mainstream of most Americans' thinking, or are generally out of step with most Americans' thinking," 56 percent said they are "out of step" and just one-third said they are "in the mainstream." These figures are a marked swing from July 2016, when only 42 percent of respondents said Democratic congressional candidates were out of step and 48 percent said they were in the mainstream.

In the July 2016 poll, Republican candidates were seen as much less mainstream than Democrats, with 31 percent of respondents saying the Republicans were in the mainstream and 59 percent saying they were out of step. A slightly higher percentage of respondents in July 2018 see Republicans as mainstream (33 percent) and a slightly smaller percentage of them see Republicans as out of step (57 percent.)

That makes the current numbers nearly identical for both parties' candidates.

The poll comes as the Democrats' left wing has continued to grow in prominence, putting moderates and the party establishment on the defensive. Self-proclaimed democratic socialist Alexandria Ocasio-Cortez scored the upset of the year by knocking out incumbent and No. 4 Democrat in the House Joe Crowley in a New York congressional primary in June.

The Democratic National Committee's leadership has praised Ocasio-Cortez, with chairman Tom Perez hailing her as "the future of our party." Perez also reached out to the left by going on a unity tour with Sen. Bernie Sanders (I., Vt.), who garnered millions of Democratic votes in his presidential primary challenge against eventual nominee Hillary Clinton in 2016.

Sanders, however, has refused to join the Democratic Party. His supporters in the party have continued to lobby for reforms in an attempt to push the party to the left.

Republican candidates continue to use opposition to House Minority Leader Nancy Pelosi (D., Calif.) as a campaign issue. Her liberal image and unpopularity around the country has gotten her criticism from moderates, while many progressives to her left have called for new leadership.