Egyptian President Abdel Fatah al-Sissi speaks at a news conference in Vienna, Austria, on Dec. 17, 2018. (Ronald Zak/AP)

SINCE SEIZING power in a 2013 military coup, Abdel Fatah al-Sissi has established the most repressive government in Egypt’s modern history. Thousands of people have been killed or disappeared at the hands of security forces. Tens of thousands have been imprisoned, tortured and, in many cases, held for years without trial. The victims are not only members and supporters of the elected Muslim Brotherhood government that Mr. Sissi deposed but also their secular liberal opponents. Mr. Sissi has packed parliament with sycophants, silenced a once lively press and squelched independent civil society organizations.

Still, he is not content with Egypt’s constitution, which, at least in theory, places some restraints on his power. So this week, his parliamentary allies are rushing to vote on a sweeping series of amendments that would make the former general a de facto dictator for life. One change would lengthen presidential terms and exempt Mr. Sissi from a two-term limit, allowing him to serve until 2034, when he would turn 80. Others would put him in charge of the judiciary, allow him to appoint one-third of the membership of a new parliamentary upper chamber and create a military council to oversee the state that Mr. Sissi would chair.

Parliamentary approval of the amendments will be followed by a referendum that the regime will likely rig. Though opponents of the power grab are trying to organize, they risk arrest or worse if they protest too forcefully.

Mr. Sissi may believe he is modeling himself after Vladi­mir Putin or Xi Jinping, who have also eliminated limits on their tenures. But Egypt’s president has shown himself to be a far less competent ruler. Rather than modernize the country’s economy, he has pursued wasteful megaprojects, such as the construction of a new capital city. While his military cronies profiteer, tens of millions of Egyptians remain mired in poverty. The former general has failed even at the military mission of defeating terrorist groups in the Sinai Peninsula.

By removing all checks on his power and tenure, Mr. Sissi will simply entrench his poor governance and raise the odds that the country will eventually rebel — as it did after Hosni Mubarak subjected Egypt to 30 years of misrule. Though his supporters, including President Trump, believe they are investing in Egyptian stability, the country’s history shows they are merely helping to ensure an unstable future for the most populous Arab country.

Mr. Sissi is aware that his extreme authoritarianism might prompt resistance in Washington, on which he still depends for billions in military aid. The website Mada Masr quotes official sources saying the rush to pass the constitutional amendments was motivated by the calculation that Mr. Trump’s support would allow them to be enacted without objection from the White House — and before the new Democratic majority in the House of Representatives trains its attention on Egypt.

Sure enough, the Trump administration has had nothing to say about the changes, including during a visit by Secretary of State Mike Pompeo to Cairo last month. As Egyptians grimly consider the prospect of 15 more years of tyranny, they have the Trump administration, as well as Mr. Sissi, to thank.