I find it hard to believe you couldn't think of a reason to not support mass migration other than 'racism', but Sweden let around a million people into a country of 10 million in an unmanaged fashion which is causing a lot of social issues? Germany where Angela Merkel let in 5 million people and the CDU lost a huge amount of support after similar things happened?

Quantify those issues. At the scale of millions of people (I'm going to assume your 50 million was a typo, not that you're innumerate or gullible), one must quantify.

If 100 people out of 100,000 who migrate cause problems, and they are all fleeing intolerable living conditions, then the only reasonable way you can say that all 100,000 should be shut out is if you value the welfare of the 99,900 so low that it is outweighed by the social harm caused by the 100 even after taking into account the benefits of migration.

Most European migrants are financial migrants rather than refugees. A journalist went to Calais during the supposed 'Syrian refugee crisis' there and found 0 Syrians.

50 million people? Germany has a total population of 80 million, so something is definitely off with your numbers. What kind of "social issues" have immigrants caused in Sweden?

5 million, typo edited. The second is easily Googlable and not under dispute by anyone.

I did Google it and I found 1.7 million refugee applications in Germany in the period 2008-2017. (https://en.wikipedia.org/wiki/European_migrant_crisis#Asylum...)

Where did you get your 5 million from?

Obviously controversial, but this could be one of the reasons some may fear immigration:

https://en.wikipedia.org/wiki/New_Year%27s_Eve_sexual_assaul...

Which is one of the worst examples ever. It was so highly politizised at the time. But you have point, it actually helped to form a certain narrative and a lot of people followed that narrative.

How is it a bad example? From Wikipedia itself...

> On 7 June, a Federal Criminal Police Office report confirmed that most of the perpetrators were of North African origin and had arrived in Germany during the European migrant crisis. Investigative results about the perpetrators were congruent with witnesses' statements.[48]

Because it was one particular case and the numbers have been looked at isolated. That and the fact that the first reports have been exagerated. Not to even speak about the way right wing groups used these reports...

I'll leave it to you to research crime numbers like rape, theft andn such for carneval in Cologne or the Oktoberfest in Munich. Because These are the numbers that provide the context.

Disclaimer: That does not in the slightest way imply that any of These cases are defendable, the least of all rape. Still, context helps to prevent knee-jerk reactions.

So because of one example, you are attributing criminal behavior to a whole group of people? Sounds like textbook racism to me.