WASHINGTON (MarketWatch) — Contentious supporters of the two rivals for the Democratic nomination turned the selection of Nevada’s national delegates this weekend into a virtual battlefield, with the chairman gaveling the proceeding to a peremptory close and fleeing the stage while armed guards cleared the meeting venue.

The spectacle of Democratic Party officials railroading through a ruling favorable to Hillary Clinton while denying certification to some 58 Bernie Sanders delegates to the state convention comes on top of charges that caucuses and primary votes around the country have been manipulated to beef up Clinton’s much-touted lead in national delegates.

Democrats have reason to worry that similar chaos could overtake a contested national convention in July as the strong-arm tactics of party officials from Democratic National Committee chair Debbie Wasserman Schultz on down provide little incentive for Sanders or his supporters to go quietly into the night.

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In fact, as the federal investigation of Clinton’s use of a private server for official emails continues to loom over her campaign, Democrats are risking a perfect storm combining the chaos of their 1968 convention in Chicago and the creeping disclosure that overtook Richard Nixon’s Committee for the Re-Election of the President.

Nixon won re-election in 1972 in a landslide even though a relatively harmless-seeming dirty trick — the break-in into DNC offices in the Watergate complex — was the subject of investigative reporting by the Washington Post and other news media.

That break-in, of course, proved to be the tip of an iceberg of malfeasance, bribery and criminality in the Nixon campaign machine that led to impeachment proceedings and the first resignation of a president in U.S. history.

The story of uncovering this scandal was a breathless drama with serendipity and grit in equal measure, making heroes of the two Post reporters — Carl Bernstein and Bob Woodward — and resulting in a bestselling book and enthralling film, “All the President’s Men.”

Are there similarities between the protracted Watergate scandal and the investigation into Hillary Clinton’s email server?

Woodward and Bernstein both have at times suggested there are, though at other times they seem to pooh-pooh the idea.

Clinton, of course, has affected a total lack of anxiety about the whole brouhaha, arguing that many of her predecessors had used private emails, that she broke no laws and that classified information was not compromised.

The FBI reportedly has some 50 agents investigating the matter, interviewing top Clinton aides and presumably Clinton herself at some point, while separate civil proceedings under the Freedom of Information Act will also depose many of those involved.

However, if there are any reporters digging away at the background to all this, they have yet to publish any revelations. That could well be because there are no revelations to discover.

But it could also be that we simply don’t have a Woodward or Bernstein, backed by an editor like Ben Bradlee and a publisher like Katharine Graham, willing to take on the government — or a Deep Throat ready to spill the beans, like the Post’s anonymous source, later revealed to be an associate director of the FBI.

Hillary Clinton is not running for re-election, but she has cast her candidacy as a third term for Barack Obama, the rival who beat her out in 2008, and as a reprise of her husband’s two terms in the 1990s.

With the Democratic Party establishment solidly behind her, she is running in many respects like an incumbent.

Is the email server issue, like the Watergate break-in, merely the tip of the iceberg? There is a whole right-wing conspiracy out there suggesting the secrecy guaranteed by a separate server has successfully hidden millions of dollars in pay-to-play contributions to the Clinton Foundation and directly to the Clintons, who have amassed a fortune in “speaking fees.”

The wheels of justice will grind slowly. Absent a new “Deep Throat” and reporters willing to listen and publish, there is little chance that official investigations will impede Hillary Clinton’s political fortunes in campaigning for the White House this year.

In the meantime, Sanders and his passionate supporters continue to offer an alternative to Clinton’s warmed-over version of progressive policies and a candidate carrying a potentially fatal load of baggage in a fight that could well go to a chaotic convention floor.

It was the 1968 Democratic Convention that marked a whole generation with its images of street riots and convention floor chaos as the party establishment railroaded through the nomination of Hubert Humphrey, who had not taken part in any of the primary elections (only 13 at the time), over antiwar candidate Eugene McCarthy.

Among the many ironies in this year’s crazy campaign is that even as the mainstream media headlines the “unraveling” of the Republican Party, Trump is slowly getting the GOP to coalesce around his candidacy and it is the Democrats, with their blinkered support of a candidate who has felt entitled to the presidency for years, who face greater risk of unraveling.