The Home Sec position is a revolving seat used as a political parking lot, so the only people who stayed more than a year and had time to move in any direction in this century were T. May and Blunkett. And the latter started in a position where he regarded civil liberties as "airy fair" and expressed the aim to make the previous law&order hard liner "seem liberal".
It seems to me that the causation is the other way around - the only people really really craving that sort of position with immense secret powers but little public spotlight are those who are intrinsically authoritarian and power hungry.
Since most politicians start out as lawyers, many will inevitably have exposure to crime. So I too appreciate the humanization of May but don't see it as an excuse for authoritarianism. In fact, these people more than any should know about the delicate balance between liberty and security.
Just to be clear, I'm not defending May's policies as either HS or PM here. I think she demonstrates both a lack of technical knowledge and a biased perspective that make her very dangerous to the public good, and as such I believe she is not the right person to serve as PM. I just think that those flaws are somewhat understandable and probably something that would affect any human being who had served in her former post for as long as she did, unless perhaps they came from a background particularly relevant to these kinds of issues. The real problem may be expecting any single individual to do what is currently required of a Home Secretary for an extended period, certainly without some sort of mandatory recovery period after they leave the post before they take any other high-level position within the government.
Do they? I guess you’re talking from a US point of view maybe.
Theresa May served as Home Secretary for about six years before becoming Prime Minister. Throughout that time, on most days she probably spent several hours just reviewing cases where the police and security services wanted to do something that required explicit authorisation at that level.
It's reasonable to assume that many, even most, of those cases really did relate to the worst in our society. It also seems reasonable to assume that in at least some of those cases someone known to be very bad could not easily be brought to justice through our normal legal processes without undermining some other ongoing investigation. In addition, she was presumably given information and advice primarily by the police and security services, and those same organisations and the officials representing them would be the people either enabled or limited by her decisions.
It isn't hard to see how someone exposed to that pressure for such a sustained period of time would become extremely authoritarian. I don't know how anyone's view of society after such an experience could not be so biased that it would be hard to see what normal life looks like any more. Just about everyone who has become Home Secretary in my adult life has moved in that direction during their time in office.
The only difference here is that by a quirk of political fate Theresa May then became the most senior politician in the UK, with a majority government that gave her the power to drive through almost any legislation if she wanted it strongly enough. She achieved that position without anyone actually voting for that outcome in the first place. Until very recently, she also had little significant opposition to challenge her.
And so here we are, with the Investigatory Powers Act on the books and a government whose most senior representatives don't seem to understand even the basics of modern technologies and their implications yet have little hesitation about proposing regulation or outright bans of some of that same technology if it makes them look strong to enough voters in the week before a general election.