By Adam Schiff and Jane Harman – The Washington Post.

Russia’s theft and strategic leaking of emails and documents from the Democratic Party and other officials present a challenge to the U.S. political system unlike anything we’ve experienced. In October, when Director of National Intelligence James R. Clapper Jr. declared that the intelligence community was confident that Russia was responsible for hacking and dumping material and that such activities could only have been authorized by Russia’s senior-most officials, he was describing a modern-day Watergate break-in, but one that was carried out by a foreign adversary through cyber means.

The unprecedented interference in our election is disturbing enough, but the damage to our democratic system was compounded by campaign rhetoric calling on Russiato hack Hillary Clinton’s email. Continued dismissals of the intelligence community’s consensus view that the most senior levels of the Russian government directed the attacks undermine those in the best position to prevent and disrupt further problems.

President Obama has ordered a full review of Russia’s meddling, which will be completed before he leaves office. But that is not sufficient. Russia’s campaign was nothing short of an attack on our democracy, and without a full and bipartisan accounting of what occurred and a robust response, trust in our institutions will be diminished.

One of us currently serves as ranking member of the House Intelligence Committee, while the other served in that capacity from 2003 to 2007. We share a deep appreciation for the importance of the oversight responsibilities the House and Senate intelligence committees carry out each day. Their work is done behind closed doors and away from partisanship for good reason.

Yet some issues are so significant to our national security that they require a coordinated investigation and response. A hostile foreign power meddling in our political system is one of those issues.

We believe a joint inquiry by the House and Senate intelligence committees is the best structure for a congressional investigation into Russian actions, intentions and potential responses. By virtue of their jurisdiction, the committee members have unique exposure to the murky world of intelligence and a full appreciation for Russia’s long history of interfering in the political affairs of its neighbors through covert means. A joint inquiry would be the most effective way to investigate what took place and avoid not only an unnecessary duplication of effort but also any discrepancies in the testimony to more than one investigative body.

There is a clear precedent for such a structure. After the attacks of Sept. 11, 2001, Congress recognized that the traditional oversight process was insufficient for an investigation of such importance and complexity, and established a joint committee on which one of us served. That committee’s recommendations were the basis for the Intelligence Reform and Terrorism Prevention Act, which fostered unprecedented cooperation within the intelligence community. While standing committees have substantial investigatory powers, their resources and staff are limited, and they cannot focus on a particular investigation. A joint committee has the added benefit of allowing Congress to speak with one voice.

A joint inquiry into Russian actions would demonstrate that this is not simply another oversight issue but an issue that goes to the core of our democracy. Will we tolerate the hacking of our elections by foreign powers if it is to the winner’s short-term benefit? If Russia is not held accountable, Moscow will continue its assault on our democratic institutions and public officials, undermining us at home and benefiting our adversaries abroad.

This congressional inquiry must provide the maximum public disclosure possible. While a thorough investigation would inevitably involve highly sensitive sources and methods, such as human intelligence or signal intercepts, to be credible, an inquiry must lean toward openness even in a field comfortable with secrecy. As with the joint inquiry on intelligence and 9/11, it would entail public hearings and the issuance of a publicly available report so that the evidence collected and presented can be independently assessed. The American people need and deserve a full account of how our elections were attacked, by whom, and for what purpose.

Other members of Congress, including Reps. Elijah E. Cummings (D-Md.) and Eric Swalwell (D-Calif.), have proposed an independent commission charged with investigating Russia’s interference, and such an idea also has merit. In the case of 9/11, the report of the joint congressional inquiry was supplemented by the independent 9/11 Commission — a 10-member, bipartisan panel that investigated the attacks and recommended major organizational changes to the intelligence community, many of which were implemented. An independent commission could complement a joint congressional inquiry by bringing to bear independent expertise and experience.

The damage Russia’s meddling caused in this election has been done, and it is immense. We can only look forward to how we respond, and that must start with a full, bipartisan and authoritative accounting. A fragmented process among many committees cannot achieve that end, but a joint congressional inquiry can. That work must start now.