Top Donald Trump supporters, surrogates and even the Republican presidential nominee himself have made a clear and concerted effort to raise questions about Hillary Clinton's health -- often in extremely suggestive and baseless ways. Our own Chris Cillizza has written twice this week about how the innuendo-laden suggestions are out of bounds. And they are.

What these attacks also are, it turns out, is ineffective.

A new Battleground poll from George Washington University tried to get at this subject in an interesting way -- without raising the specific allegations made about Clinton's health, or even mentioning that such allegations existed.

The bipartisan pollsters -- GOP firm Tarrance Group and Democratic firm Lake Research Partners -- simply asked whether people think the phrase "is healthy enough to be effective" better describes Clinton or Trump. It was the last of seven descriptors in which people had to choose between the two.

According to this poll, slightly more people think Clinton is "healthy enough to be effective" (43 percent) than Trump (41 percent). That's exactly the same margin by which Clinton leads overall -- 42 percent to 40 percent -- and it suggests pretty strongly that the "healthier" attacks aren't landing with much force -- or at least not enough force to make a dent in the typical partisan divide.

Clinton is the only major candidate with well-publicized medical issues in recent years. Her 2012 concussion and an ensuing blood clot are no secret and have seeded much of the rumor-mongering during the 2016 campaign. Trump, meanwhile, was declared by his doctor to be healthier than any of our 43 previous presidents and to have a remarkable bill of health, despite being 70 years old. Trump's doctor's letter is as hyperbolic as it is uninformative, with basically nothing to indicate any major health problems. So there is really no similar seed of doubt when it come to Trump's health; and yet, on the question of health, Clinton comes out slightly ahead.

And yet a majority thinks Clinton is clearly healthy enough. An additional 9 percent chose "both equally," so that's 52 percent who say either that Clinton is the healthier of the two or that they are equally healthy. This suggests that many undecided or third-party voters have no qualms about Clinton's health.

Clinton has other vulnerabilities. She trails when it comes to which candidate is more honest and trustworthy, 39 percent to 35 percent. She also trails on which candidate says what they believe, 59 percent to 30 percent. And she's down one point on who is the stronger leader. So it's not as though her backers and swing voters don't recognize her vulnerabilities; they just don't think her health is one of them.

The fact that claims questioning Clinton's health status may be baseless and underhanded probably won't slow the attacks. The fact that they're ineffective might.