By Johan Ahlander STOCKHOLM (Reuters) – The populist, anti-immigration Sweden Democrats’ rise to real power after Sunday’s election has civil rights groups and many immigrants worried about what the future might hold in a country long known for tolerance and openness. Social Democrat Prime Minister Magdalena resigned on Thursday, meaning Moderate Party leader Ulf Kristersson must now try to form a new government. He cannot do so without the support of the Sweden Democrats, who became the second biggest party with 20.5% of the votes. The gains for the Sweden Democrats come on the back of what m…