Russian President Vladimir Putin. (Pavel Golovkin/Associated Press)

President-elect Donald Trump won the 2016 presidential election and will be the next president of the United States. As I have written before in these pages, the rules of the game for choosing our presidents need to be changed, but that discussion concerns future elections, not this past one. A win is a win.

That most people acknowledge Trump’s victory should now free us to have a serious discussion about the role of foreign interference in the 2016 presidential election. During the campaign, mentions of foreign meddling quickly became partisan and polarized, blocking any real examination of the facts, let alone a discussion of prescriptions. Even Obama administration officials seemed to tiptoe around these issues, not wanting to appear to use their privileged access to classified information to help the Democratic Party’s candidate, Hillary Clinton. But now the election is over. Before the next one, we need to know the facts — investigate what did and did not occur — so that we can develop procedures, policies and laws to strengthen the integrity of our electoral process before 2020. This is not a partisan plea; it is a national security issue.

CIA officials told senators it is now "quite clear" that electing Donald Trump was Russia's goal. In an interview on Fox News Sunday on Dec. 11, President-elect Trump denied the CIA's assessment. (Victoria Walker/The Washington Post)

We know some facts, and they are disturbing. For instance, we know that Russian actors stole data from people working at the Democratic National Committee. We know that another foreign actor, WikiLeaks, published data stolen from the DNC to adversely affect Clinton. We also know that WikiLeaks and others published data stolen from John Podesta, Clinton’s campaign chairman, in order to try to damage further the Democratic candidate. We also know that WikiLeaks did not publish similar kinds of data from the Trump campaign or the Republican Party.

We do not know precisely if the Russian government or its intermediaries transferred the data they stole to WikiLeaks. We do not know with certainty if the Russian government (or any other actor) stole data from Trump and the Republican Party but chose not to release it to WikiLeaks. We do not know if WikiLeaks had obtained data on Trump and the Republican Party but made an editorial decision not to release this information. I don’t know, but we need to know.

We also know that Russian hackers were probing computers that contained information on voter registration, and poking around at actual voting machines and tabulators. Thankfully, this clear Russian capacity to disrupt Election Day activities, including vote counting, does not seem to have led to actions influencing the election outcome. But what about the future? National popular votes are less vulnerable to hackers because manipulating millions of votes without detection is difficult. But our electoral college system makes us more susceptible to tampering, because simply under-counting a small fraction of votes in a few targeted precincts of a few key states can change the electoral outcome. Despite our federal, decentralized system of voting, can we nonetheless implement measures to prevent voting fraud in 2020, when technologies to manipulate voting data will have improved? I don’t know, but we need to know.

The Post's Ellen Nakashima goes over the events, and discusses the two hacker groups responsible. (Jhaan Elker/The Washington Post)

And what about the capacity of other actors, both foreign and domestic? Will they now be more tempted to engage in voter manipulation in 2020? Are there policies and negotiations that, if started now, could prevent such actions by 2020? Should there be international norms about regulating such behavior, as disrupters have made clear their intention to intervene in future European elections? We need to know.

In addition, we know that Russian-government-controlled “media” outlets such as RT and Sputnik campaigned openly for one candidate, Donald Trump. Sputnik even tweeted the hashtag #CrookedHillary. We have laws preventing foreign governments from contributing financial support to candidates. Should we have similar laws about in-kind support? Such regulation seems hard, in tension with our First Amendment, but shouldn’t our lawmakers wrestle with the issue? Should Sputnik and RT employees be accredited as journalists or as foreign agents under the Foreign Agents Registration Act? I don’t know. But we need to know.

Stories also have circulated about Russian and other foreign actors involved in the production of fake news, as well as collaboration between Russian (and other foreign) and American leaders and movements regarding common political agendas, that is, a new “Illiberal International” to replace the old Communist International. What was the full scope of these activities? Did any of these actions influence the election outcome? I don’t know, but we need to know.

The Obama administration just announced that it plans to conduct an investigation of Russian cybertheft during the 2016 election.

That is a good start (although let’s hope this investigation started long before now!), but it is not enough. First, a serious investigation will take longer than one month; second, the authors of such a report must be bipartisan; third, the scope of such an inquiry must include other forms of interference beyond hacking; and fourth, the actions (and maybe non-actions) of the executive branch during the 2016 campaign must be part of the study.

The only way to generate comprehensive answers to these questions and many more concerning the integrity of our electoral system is for Congress to authorize and support a bipartisan investigation, staffed in part by academics and experts, so that we know better what happened and therefore can make important policy changes before the 2020 elections. Such an investigative commission is exactly what Reps. Elijah E. Cummings (D-Md.) and Eric Swalwell (D-Calif.) proposed this week in their new bill, the Protecting Our Democracy Act, which would establish “the National Commission on Foreign Interference in the 2016 Election.” Ideally, the act could be expanded to include H.R. 5181, the Countering Foreign Propaganda and Disinformation Act of 2016, as these issues must be analyzed and addressed together, and not treated separately.

All Americans — Republican, Democrat and other — should want free and fair elections. We must diagnose the problem, including dispelling possible myths about the extent of the problem, before recommending prescriptions. Establishing this commission is an excellent bipartisan step toward preserving this most sacred American value.