Israeli Prime Minister Benjamin Netanyahu aims to bolster U.S. support for his country’s fight against Hamas and other Iran-backed armed groups in a speech to Congress Wednesday even as many Democratic lawmakers plan to boycott it and protesters amassed around the Capitol to condemn the war in Gaza and the humanitarian crisis it has created.

Netanyahu also wants to portray himself as a respected statesman for an increasingly critical audience back in Israel, but that task is complicated by Americans’ divided views on Israel and the war, which has emerged as a key issue in the U.S. presidential election.

Tall steel barriers ringed the Capitol Wednesday, and security officers were deployed on foot, bicycle and with dogs. Thousands of protesters rallied near the Capitol ahead of the Netanyahu’s speech, denouncing him as a “war criminal” and calling for a cease-fire. Police tussled with demonstrators seeking to block the prime minister’s route. Netanyahu is assured a warm welcome from Republican lawmakers who arranged his speech in the House chamber. The appearance will make him the first foreign leader to address a joint meeting of Congress four times, surpassing Winston Churchill. Some leading Democrats and political independent Bernie Sanders plan to boycott Netanyahu’s speech. But the most notable absence will be right behind him: Vice President Kamala Harris, who serves as president of the Senate, said a long-scheduled trip will keep her away.

The next Democrat in line, Sen. Patty Murray of Washington, is declining to attend, and former House Speaker Nancy Pelosi said she would be meeting with families of Israeli victims of Hamas instead.

Republicans said the absence of Harris, the new Democratic front-runner for the presidency, was a sign of disloyalty to an ally. Former President Donald Trump’s running mate, JD Vance, said he would also be a no-show for Netanyahu’s speech, citing the need to campaign.