Word or phrase for this particular action

Question

What do you call when someone does something that they already wanted to do but only do it because they saw someone else do it?

For example the Brexit business, or America after Trump became president. After these phenomenons people started saying racist things, and it kind of revealed what they actually wanted to say, but only did so because other people were doing it too. They probably know it's bad, but they want to say it, and they do because other people are saying it too, I assume.

I'm giving a presentation on Brexit and the title would be something like this: "Brexit and racism: causation, correlation and _______"

Answer 1

I would suggest:

Brexit and racism: causation, correlation, and polarization

While not an exact fit to the circumstance you describe, I think it is a suitable notion given the political nature of your topic.

In the world of politics, polarization (or polarisation) can refer to the divergence of political attitudes to ideological extremes. Polarization can refer to such divergence like public opinion or even to such divergence within certain groups. Almost all discussions of polarization in political science consider polarization in the context of political parties and democratic systems of government. When polarization occurs in a two-party system, like the United States, moderate voices often lose power and influence.
_Wikipedia

The notion would be that because of the polarized political atmosphere, the electorate attempts to align themselves with some extreme group that seems to offer a safe political option. The consequence is that you may find a growing cluster of people that promote racism.

Answer 2

The common phrase for this is "monkey see, monkey do" but that probably doesn't fit as the title of a serious presentation.

More generically, it's a form of mimicry, or you could say it was because the second group was emboldened by the actions of the first in a case of "follow the leader".

Answer 3

A currently fashionable word for coordination of behaviour in this way is meme defined as

An element of a culture or system of behaviour passed from one individual to another by imitation or other non-genetic means.

Completing your title as "Brexit and racism: causation, correlation and the development of memes" may suit your purpose well

Answer 4

Uninhibited, or Loss of Inhibition

When people don't do something they otherwise wish to do, it is usually do to some sort of inhibition. When situations change, they may lose their inhibition to do the things they wanted to, but were otherwise kept from doing through social or political pressure.
From Merriam-Webster:

inhibition

noun

1:
a: an inner impediment to free activity, expression, or functioning: such as a mental process imposing restraint upon behavior or another mental process (such as a desire)
2:
b: something that forbids, debars, or restricts