> The Americans impeached this president once and nothing happened,
Twice; there have been four impeachments of US Presidents, two of which were of Donald Trump during his previous term.
> Do Americans have optimism that Trump won't be their first dictator for life and will actually face consequences for his crimes?
I'm pretty confident that he WILL be a somewhat [0] dictatorial leader for life, but I think there are pretty good odds that this does not involve exceeding the maximum term limit set by the 22nd Amendment.
[0] somewhat only in that I don't think the total destruction of institutions that would make it an absolute dictatorship rather than an aspirational one that still struggles against things like courts that, while mostly tame, still give some effect to Constitutional rights and limits is likely to be completed before Trump is, though not for lack of trying.