I took this to be strategic statement, which the President later tried to explain [indicating that was not the case for tactics]. But your average voter doesn't understand the difference, and with the MSM against him and not willing to explain it, this statement was a huge negative for Republicans. The public can't be addressed with the same terminology used when meeting with the Sec. of Defense.
I explained it to someone the other day that it's like you're flying from point A to point B. Along the way you determine the wind is blowing you off course, so you make some adjustments to your heading to correct for the wind. You are still going to point B, but you've changed the course to take into account conditions you encountered along the way. "Stay the course" was probably a bad choice of words. I'm afraid too many people took it to mean the President was satisfied with the situation and had no intentions of changing anything. That was not the phrase to have used. Besides, it was the catch phrase of a campaign several years ago and old campaign slogans don't usually work. Someone needed to remind the voters every day that getting to point B is a worthy goal and although the course is being altered a bit, we're still on our way to point B!