The problem with these discussions is that we seldomly use common definitions, which creates more heat than light. There was a strain of late 20th Century American conservatism that was rooted in fiscal restraint, loosely regulated free markets, and a privileged place for the nuclear family, civic duty, and the church as the glue holding (small) communities together. I'd vehemently disagree with most of these as policy anchors, but none of them are beyond civil discussion per se.
But here's the problem: this late 20th-Century old school conservative thinking has been thoroughly hollowed out and co-opted to the point it is now completely meaningless. (The last administration was neither fiscally restrained, family oriented, nor in any way tied to any recognizable New Testament 'love thy neighbor' teaching. Yet, modern 'conservatives' can't get enough).
Into these conceptual containers has been smuggled a toxic strain of (white) (Christian) (popular) nationalism ... some may use the 'F' word ... that is fundamentally anti-democratic, anti-science, intolerant, and is now emerging as violent - not just to vulnerable groups, which is a show stopper in itself - but to the whole damn country and democratic process. You don't debate people like that. You crush them at the ballot box (or at Gettysburg or the beaches of Normandy if it comes to it).
So (pardon the TED talk), I think if someone wants to show up and debate whether we should be running budget deficits in excess of 3% of GDP, or whether we are regulating nuclear power too tightly, or whether industry X should be privatized/nationalized, they are probably good (at least by me - I can't speak for others). But there is an understandable level of suspicion around the whole 'conservative' discourse, and if someone tries to smuggle ethno-nationalism, economic Darwinism, or bigotry toward vulnerable groups into the discussion under the guise of 'traditional family values' and 'fiscal restraint' ... they are going to have a tough time.