The phrase "a much bigger margin" is correct and usable in written English.
It can be used when comparing differences in size, quantity, or degree, often in contexts like finance, statistics, or competition.
Example: "The company reported a much bigger margin in profits this quarter compared to last."
Alternatives: "a significantly larger margin" or "a considerably greater margin".
After Ford won Illinois (by a much bigger margin than Romney did Tuesday), his camp started organizing appeals for Reagan to drop out and unite Republicans.
Thing to watch out for: Be cautious of polling on this state because there's little of it, which means a much bigger margin of error.
And I think, you know, it — not only did it win, but it won by a much bigger margin than people thought it would happen.
Most important, it would give banks a much bigger margin of error, and make it less likely that taxpayers would end up on the hook when things went wrong.
Trump was ahead by a much bigger margin than the models had anticipated — "and, in fact, a larger margin than Romney had beaten me in these areas, or McCain had beaten me in these areas".
He went on to criticize the two main polls before the voting that helped lead many news outlets to expect that Mr. Kerry would beat Mr. Edwards by a much bigger margin than he did.
The good news for them is if you don't like something, hey, caveat emptor, and also they can make a much bigger profit margin on used records than they can on the new stuff they sell, so it's a nice double dip if they can sell something twice.
Pelosi and her allies pointed to the top-line reality of Ohio: A district that voted for Trump in 2016 by 11 points and for Republican congressional candidates by much bigger margins swung decisively to Democrats.
But instead, we saw the opposite result: Sanders' platform lost, and lost by much bigger margins than Clinton did.
You could make much bigger margins on recorded music, and it was very easy to stick a house or techno record out, which might today sell 200-300 copies, which back then would have sold 3,000, 4,000, 5000 even more maybe.
So mathematically, as it gets bigger and bigger, that accelerated revenue growth has a much bigger impact on the margin of the overall entity.
