The number of hate groups in Pennsylvania rose to 40 last year, up from 38 the year before, according to a recent report by the Southern Poverty Law Center.

Its Spring 2016 Intelligence Report, "The Year in Hate and Extremism," features Republican presidential candidate Donald Trump on its cover. In it, a senior fellow at the SPLC called 2015 a year of "horrific political violence."

"The violence arose in a landscape dominated by losses for those on the political far right," senior fellow Mark Potok wrote.

"Hard-liners were enraged by the Supreme Court's legalization of same-sex marriage; pressure to accept Syrian refugees; President Obama's executive orders meant to stall deportation of many undocumented workers; the attack on the Confederate battle flag that resulted from a flag-enthusiast's mass murder in Charleston; and the demographic browning of the U.S. population," Potok wrote in an editorial.

The nonprofit SPLC, based in Montgomery, Ala., found that nationwide, active hate groups rose to 892 in 2015, from 784 in 2014.

Pennsylvania had the sixth-highest number of hate groups after Texas (with 84), California (68), Florida (58), New York (44), and Tennessee (41), the SPLC found.

Among the 40 active hate groups in Pennsylvania, the SPLC listed six as being in the Philadelphia area, including the Maryland-based Traditional Rebel Knights of the Ku Klux Klan and the Harrisburg-based Keystone State Skinheads, now Keystone United.

A woman who answered the phone number listed on Traditional Rebel Knight's website hung up on a reporter Saturday.

Also listed were the black separatist groups the Israelite Church of God in Jesus Christ, based in New York; the Baltimore-based Israelite School of Universal Practical Knowledge; and the Chicago-based Nation of Islam.

The SPLC also listed the Washington-based As-Sabiqun group, an American Muslim group, as a hate group in Philadelphia.

Email messages seeking comment sent to Keystone United, the Israelite School, and As-Sabiqun were not immediately returned Saturday. A contact number for The Jesus Christ group could not be immediately located.

No one was available to comment Saturday at the Nation of Islam's national office. A man who answered the phone referred a reporter to the Final Call website, which he said was the official newspaper of the Nation of Islam.

In an April 2013 article, Nation of Islam Minister Louis Farrakhan decried the SPLC's labeling of his organization as a hate group and called for a showdown.

"First, 'hate' is always manifested not just with words but with deeds . . . ," he said. "If we are haters, why can't you show me some hateful act that we have done other than our telling the truth that exposes your lies and your deceit? So let's have the showdown. I love the term 'showdown.' "

shawj@phillynews.com215-854-2592@julieshawphilly

Staff writer Rob Tornoe contributed to this article.