We can see on current polling that about 40% of the GOP is aligned to a so called moderate. Hillary's own standing skews the Democrat view, but there would likely be a third of them similarly aligned. Critically though, they'll be in states like New York, and the New England commonwealth
Trump's the most extreme candidate the US has had since George Wallace. "We'll bomb the shite out of ISIS", which perhaps isn't completely without precedent in that Barry Goldwater tried justifying the use of nuclear bombs in 1964
The last candidate to stand whom you could genuienly stick the label of a liberal on was Michael Dukakis. He got gubbed. Bernie is more left leaning than Dukakis, or at the very least, the same as him (given the shift in the centre of gravity).
The last Democrats who you might describe as having some semblance of Socialism or redistributionists to them were Hubert Humphrey and George McGovern, both were slaughtered
There is potentially a big chasm in the middle. There's enough room for all three rather than the traditional centerist squeeze
Trump = Farage
Sanders = Corbyn (probably not true - but humour me! - use Andy Burnham if it sits a bit better)
Either way, there would be room for someone like George Osborne on that spectrum, and there will be for Bloomberg if it comes to pass, but this is the big question .... if you can answer the IF question, you can make a good decision I reckon
Even at 33/1 though you don't require too much to still justify it. Bloomers is a sight more credible than Perot
However, I just don't really detect that he's managing expectations and the build up to an announcement in perhaps the way someone would be doing if they were leaning towards a run