You're right he is concern trolling. Some context for the Duke statement, to be fair.
... Gabbard received this bizarre, perhaps disingenuous trolling endorsement from the virulent anti-Semite Duke despite several moves signaling her potential support for Israel. American Evangelicals, Israel and U.S. Jews have a long and at times hypocritical political relationship.
Gabbard, unlike many Democrats under the Obama administration, attended Israeli Prime Minister Benjamin Netanyahu's controversial March 2015 speech to Congress.
Israeli media ranging from Haaretz to the Times of Israel are blasting Democrats this week for refusing to support Republican Sen. Marco Rubio's "anti-BDS" legislation that would block any Boycott, Divestment and Sanctions moves against Israel. Newly elected Democratic Rep. Alexandria Ocasio-Cortez of New York and the first two Muslim women elected to Congress this past year -- Michigan's 13th District Rep. Rashida Tlaib and Minnesota 5th District Rep. Ilhan Omar -- are being lambasted by criticism from conservative Israeli figures.