Help! Can footage be salvaged with Resolve, somehow?

I had some bad luck. I was doing a six hour shoot and one segment of the six hours went bad. Here is what happened: I was recording a panel of speakers, five people are at a table. Three of the five speakers from the left are in focus, two on the right are not. My lens sometimes does this, where, for whatever reason, parts of an image are not in focus, like a haze sort of covers one side. My camera screen is not not very large (nor can I afford and external monitor at the moment) and the speakers are all the same depth of field. Also, unfortunately, the stage they were speaking on did not have functioning lights nor did they did not want my spotlight on them because they did not want to be blinded. Excuses, excuses, yeah, I know. The other footage bits of sharp enough. I think (with regards to the haze) it is a light issue, where when the rays hit the lens a certain way, I get that haze. But I could be wrong.

Unfortunately, the second person from the right is speaking. What tools are there in Resolve to get the speaker some kind of focus/sharpness?

masks to isolate the area of concern
de-haze to increase contrast
there's a few sharpen tools on offer, in my experience, best is Saphire, then BCC, but the native tools are workable

You'll never be able to make it good, but you might be able to make it somewhat better. Next time, don't let the talent or the venue affect your ability to do a good job.

Can't give any better advice than what you already got.
But I'd like to mention that this sounds like you have a broken lens if all the speakers were more or less at the same distance (you wrote DoF, though) and should have been in focus. You lenses mount might be damaged.

You might be experiencing lens flare, too, if it's a bright light hitting your lens. JJ Abrahms pays extra for that!

When shooting, make sure you have the lens shielded from lights pointed at the camera - that's what a matte box with side and top flags is for. You can do this with a flag, black foil, your hand, etc. Light pointed INTO your lens can affect the picture dramatically. As previously remarked, you may also have a broken lens or lens mount if the focus is not linear across folks who are at the same focal distance (I assume that's what you mean by depth of field?)

You don't mention what kind of camera you have - small sensor or large. On a small sensor camera, like a typical inexpensive video camera, the whole world should be pretty much in focus, if any of it is, which would indicate a broken lens or a lens flare. On a large sensor camera, like a DSLR, low light levels lead to very shallow depth of field, meaning only things at the exact same distance from the lens will be in focus, and there is only a very short distance from front of the area in focus to the back of the area in focus. (Consider googling 'DOF' for a better understanding of the term, because I think you're mis-using it.)

Hopefully I'm not explaining the obvious, forgive me if I'm insulting, not intending to be, but the details in your question imply you're new-ish at this.

If I understand the problem correctly: The best trick for this scenario involves masking around the area that's out of focus and has lower contrast. Do that in a new node, make the mask edge nice and soft. Then adjust the contrast or lift and gain to match, as best you can, the area that looks better. Open the scopes, they will help you with that. Then, go to the blur setting, and add sharpening - basically negative blur. Only use a little as it gets really obvious when you add a lot. Depending on the resolution I don't like to go any lower that 40, mostly I stay around 44-46.

So, the next part of the trick is crappy, but sometimes has to be done. (It's actually very common in visual effects) Essentially, lowering the overall quality of the image so the 'problem area' (or VFX) doesn't stand out. In your case, add an 'outside node' (which selects the part of the image opposite of the mask you just made) and add just the tiniest bit of blur to the 'good' parts of the shot.

If you're successful, the whole thing will look slightly softer, but also more uniform. It won't hide the problem completely

I've had to do this for clients that shot something with a phone or handicam - and their autofocus picked the wrong part of the shot. It's not ideal, but it will often fool the eye and solve your problem aesthetically. Good luck!

If it makes sense for your case, adding some text or graphics can help after using the advice Greg gave you.
The human eye wants something to hold on to and some in-focus information in the frame will make the soft image less objectionable.

I had some bad luck. I was doing a six hour shoot and one segment of the six hours went bad. Here is what happened: I was recording a panel of speakers, five people are at a table. Three of the five speakers from the left are in focus, two on the right are not. My lens sometimes does this, where, for whatever reason, parts of an image are not in focus, like a haze sort of covers one side. My camera screen is not not very large (nor can I afford and external monitor at the moment) and the speakers are all the same depth of field. Also, unfortunately, the stage they were speaking on did not have functioning lights nor did they did not want my spotlight on them because they did not want to be blinded. Excuses, excuses, yeah, I know. The other footage bits of sharp enough. I think (with regards to the haze) it is a light issue, where when the rays hit the lens a certain way, I get that haze. But I could be wrong.

Unfortunately, the second person from the right is speaking. What tools are there in Resolve to get the speaker some kind of focus/sharpness?

A picture or a few seconds video would help.