It shows Merkley leading Republican state lawmaker Jason Conger by 16 points and Dr. Monica Wehby by 20 points.
The poll was conducted on behalf of Democratic Senator Merkley's campaign. It involved 600 likely general election voters statewide and 400 likely Republican voters.
The interviews were conducted last week.
This poll supports a poll out of a couple weeks ago that shows Merkley defeating his Republican challengers -- though by lesser margins.