There is a grave question confronting this nation: Did the Kremlin wage covert cyberoperations to affect the outcome of the U.S. election? A secondary, even more troubling issue must also be addressed: Was anyone from President-elect Donald Trump’s campaign involved or aware?

The CIA and FBI have known for months that individuals in Russia hacked into servers of the Democratic National Committee, the Republican National Committee and others, but a direct connection to the Kremlin remains unproven. Nevertheless, CIA officials recently concluded that the hacking was a deliberate attempt to tilt the election to Trump, and briefed congressional leaders on their report. That is a serious charge that deserves a full congressional examination.

As early as mid-November, Adm. Michael Rogers, the director of the National Security Agency, said the Russian hacking that resulted in a flood of damaging Democratic e-mails from WikiLeaks was “a conscious effort by a nation-state to attempt to achieve a specific effect,” and not something “that was done casually.”

Now, with the CIA report, it has become imperative that Congress hold hearings that will put this issue before the public. Republican Sen. John McCain once again has proved a courageous and forceful voice within his caucus, demanding a select committee, which can perform functions beyond the authority of a standing committee. Senate Majority Leader Mitch McConnell has rejected the former in favor of the latter. But McCain is right. This is a matter of vital national security interest that requires a bipartisan committee specifically dedicated to it. At issue is the integrity of the U.S. election process, possible backdoors into government operations, and the potential warming of Russian relations that Trump has made clear he wants to pursue. This country could not even consider easing sanctions against a nation that may have deliberately attempted to undermine a presidential election. A story by the New York Times on Tuesday noted that a cyberespionage gang linked to the Kremlin had been found rampaging through the unclassified e-mail systems at the White House, State Department and Joint Chiefs of Staff prior to 2015. More leaks could well be coming.

Trump’s immediate dismissal of the CIA analysis as “ridiculous” impugns a top intelligence agency that is supposed to provide this nation’s leaders with highly classified information on the world’s most sensitive matters. His response, coming as it does against the backdrop of skipped daily intelligence briefings, betrays a shallowness that should chill Americans.

Trump’s campaign included operatives with close ties to Russia, and Trump himself has broken with GOP doctrine to extol the virtues of brutal Russian strongman Vladimir Putin. Trump’s pick for secretary of state, Exxon Mobil head Rex Tillerson, for decades managed his company’s interests in Russia, and in 2013 Putin awarded Tillerson the country’s “Order of Friendship.” For all the attributes Tillerson may bring, he also is dogged by an enormous conflict: His company stands to gain billions if sanctions against Russia are lifted.

It is not enough for Trump to tell voters that the election is over and that it’s time to move on. The CIA has not been without its controversies and even intelligence failures. But there appears to be mounting evidence here that something is seriously awry, and Americans should be wary of anyone too quick to try to squelch what is still emerging.

Democratic Minnesota Sen. Amy Klobuchar, who earlier called on Trump to stand with Ukraine against Russian aggression, has joined McCain and others, saying that “Russia’s role in the 2016 election warrants a full and thorough congressional investigation.” Other members of Congress, including the rest of the Minnesota delegation, should add their voices to the growing chorus.