It is important to acknowledge that Donald Trump is legally and constitutionally president. Investigations are not an effort to undermine Trump’s presidential legitimacy, but to understand and then respond to a far-reaching and grave assault on America’s democratic process. Whatever opposition or outrage Democrats and other Trump critics may feel over his policy directions—on energy, climate change, the minimum wage, taxation, or whatever—is an issue entirely separate from the defense of democratic norms and institutions.

The president-elect could enhance confidence in his presidency by endorsing the call of Senators McCain, Graham, Schumer, and Reed for a bipartisan select committee of Congress to undertake a “comprehensive investigation of Russian interference” and develop “comprehensive recommendations and, as necessary, new legislation to modernize our nation’s laws, governmental organization, and related practices to meet this challenge.” But should Trump continue to show cavalier disinterest in learning the facts of Russia’s cyberattacks, and then a readiness to lift sanctions on Russia even in the face of this and similar mounting efforts against European democracies, disturbing questions will be accentuated.

Beyond determining and then publicly reporting what Russia did to hack the 2016 election campaign, how and why it did it, and how the United States can prevent similar or worse sabotage in the future, the nature of the contacts between any elements of the Trump family or organization and the Russian state is also a question for investigation. In September, the journalist Michael Isikoff reported that U.S. intelligence officials were seeking to assess the nature of meetings this past summer in Moscow between Carter Page, whom Trump identified in March as one of five people he turns to for foreign-policy advice, and “senior Russian officials close to President Vladimir Putin.” Page, who worked in Russia as an investment banker during the previous decade and now has extensive business ties there, gave a speech this past summer criticizing the U.S. and other Western democracies for a “hypocritical focus on ideas such as democratization, inequality, corruption and regime change” in Russia. He reportedly resigned in September as a Trump campaign advisor, denying that he had privately communicated with top Russian officials, but he was back in Moscow earlier this month.

Other questions concern the extent of commercial and financial ties between Trump and Russian interests. What is the nature of any interactions between his family members or advisors, and officials or business allies of the Putin regime? What is the nature of the ties he himself forged during his 2013 visit to Moscow for the staging of his Miss Universe pageant?

Trump may well be clear of dangerous foreign entanglements, but there are enough questions and unknowns to warrant full investigation—not to mention full disclosure by Trump, including his tax returns. The American people deserve to know at least this much about a leader who is now preparing to deal with the most pressing challenge confronting the security of the United States and its European allies: a resurgent authoritarian Russia that is assaulting the very foundations of Western democracies.

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