(CNN) More than half of American adults say they believe it's likely there will be Russian interference in November's midterm elections, according to a new NPR/PBS NewsHour/Marist poll released on Wednesday.

The 57% of Americans who believe there will be interference represents a new high since the poll began tracking the question in February, when only 41% of Americans said the same.

The most likely to believe Russia will meddle in the midterms are strong Democrats (77% likely), those who live in suburban areas (68%), and whites who graduated college (67%). The groups most likely to say Russia won't do anything are strong Republicans (63%), Donald Trump supporters (58%), and white evangelical Christians (54%).

Only a week after downplaying Russia's interference in the 2016 US elections, Trump tweeted Tuesday that he was "very concerned" about Russia meddling in the 2018 midterms -- but on behalf of the Democrats. The poll was conducted days before that tweet.

I'm very concerned that Russia will be fighting very hard to have an impact on the upcoming Election. Based on the fact that no President has been tougher on Russia than me, they will be pushing very hard for the Democrats. They definitely don't want Trump! — Donald J. Trump (@realDonaldTrump) July 24, 2018

Sixty-nine percent say they believe there was Russian interference in the 2016 election, compared to 24% who said there wasn't.

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