A new poll is showing a surprising turn in the race for one of Montana's seats in the U.S. Senate, and the "blue wave" narrative.

Here's what the poll says

According to an internal poll for the National Republican Senatorial Committee, the Republican challenger Matt Rosendale leads the incumbent Sen. Jon Tester (D) by 2 percentage points, with 47 percent of the vote to Tester's 45 percent.

While the lead falls within the error margin for the poll (+/- 4 points), every poll has shown Tester in the lead, so this could signal a turn toward Rosendale in the race.

It could also squelch Democratic hopes for a "blue wave" in the midterm elections.

Previous to this poll, the Real Clear Politics average for the race had Tester winning over Rosendale by 5.5 percentage points.

What might have moved the needle against Tester?

President Donald Trump appears to have made the Montana Senate race a priority. After all, it was Tester who helped sink the president's nomination, Ronny Jackson, for the head of the department of Veterans Affairs.

Trump has already visited Montana once to campaign for Rosendale, and so has his son Donald Trump Jr.

Rosendale has embraced the president's support. He tweeted, "There’s still a lot of work to do but it’s encouraging to know we’re up 2 points against @JonTester!"

"The contrast couldn’t be greater: I’ll support President Trump," he added. "@JonTester won’t."

What else?

More recently, the election made headlines when the rock group Pearl Jam published a publicity poster with a cartoonish representation of the president's corpse in front of the White House. The poster was in support of a concert to raise support for Tester.

Rosendale called the poster "disgusting and reprehensible," and called on Tester to denounce it.