I don't think proof of life existing on Mars would cause any hysteria. It would make a lot of science nerds very happy, but the average Joe would probably give a welcome nod and think little more about it. The public appeal of something akin to an archaea is always going to be limited.
The trouble with Mars is so far it can't be determined if life is there from what we have seen. The planet looks like a dead world and behaves like a dead world. Based on that we can determine 3 hypotethetical scenarios, one of which will be true. 1: Mars has always been abiotic, it was cloudy and wet at one time but did not result in life. 2: Life did form on Early Mars but the biosphere suffered total collapse with the planet's climactic shift. 3: Mars did form life, and it's still clinging on today, but has retreated from the surface where it is too hostile.
For now you can speculate on which option you prefer.
I am slanting towards option 1 personally, but have no more idea if I'm right than anyone else. Future investigations will hopefully help us narrow the question further.
I suppose just for fun you can add option 4: Mars does contain abundant life but NASA are covering it all up under orders from their Illuminati masters carrying out the Reptilian masterplan from their starbase on the Holo-Moon.
Of course you'd be required to have special needs to buy into any of that.
Incidentally, millions of dollars is actually pretty cheap in space exploration terms. Even the cheap stuff tends to cost in the billion range, but the cost is less eyewatering when you consider that they are lifetime costs and that can be 20 years in case of some missions. Hawking, like the rest of us just wants to know. But like the rest of us, he'll just have to wait and see.
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