On Monday, campaign finance reform activist and Harvard law professor Lawrence Lessig announced he was ending his long-shot campaign for the Democratic presidential nomination.

Lessig blamed the national Democratic Party for, he said, changing the rules in a way that made it impossible for him to qualify for the party's next debate. "It is now clear that the party won't let me be a candidate," he said. "I must today end my campaign for the Democratic nomination." Watch his announcement below:

Lessig said nothing in his video to indicate that he was leaning toward an independent presidential candidacy. However, he did say he was going to "turn to the question of how best to continue to press" for "reform now."

Specifically, he said, his goal was to "fight to fix the failed institution at the core of our democracy, Congress" — and to convince the American people that "we can't solve any of the problems that this nation must address until we fix the crippled and corrupted institution of Congress first."

In the past, Lessig had mused about recruiting House of Representatives candidates who'd run as "referendum representatives" backing his major reform bill, the Citizen Equality Act. (The proposal isn't finalized, but it would give small donors vouchers for campaign donations, overhaul how House members are elected, and make voting easier.)

But Lessig's previous effort to influence congressional elections — Mayday PAC, which spent more than $10 million in an effort to elect candidates who supported campaign finance reform in 2014 — is widely viewed as a failure, since the candidates he backed overwhelmingly lost. So it's unclear what his next move will be.

Lessig says Democrats changed their rules so that it would be impossible for him to qualify for debates without "time travel"

Since Lessig announced his presidential campaign less than two months ago, he's gotten little attention or traction in the polls. So he pinned his hopes on qualifying for a Democratic debate. Perhaps once he brought his message to a national audience, his bid would catch fire. "I may be known to tiny corners in the tubes of the internets, but I am not well-known to the American public generally," he says in the announcement. "Our only chance to make this issue central to the 2016 presidential election was to be in those debates."

To qualify, Lessig thought he had to hit 1 percent support in three major national polls in the six weeks before the debate, and he says that DNC staffers he spoke with confirmed this. That proved difficult, since many pollsters didn't even bother to include Lessig's name as an option, and when they did he often didn't do very well. So he missed the cut for the first debate — but he had hit that 1 percent threshold in one live-interview phone poll (from Monmouth) and a few internet polls so far, so he hoped he was on its way.

But according to Lessig and his adviser Steve Jarding, the DNC suddenly informed them last week that the rules were different. Now, instead of hitting 1 percent in three polls in the six weeks before the debate, they had to hit 1 percent in three polls conducted over six weeks before the debate. (This is very odd because debate qualification is usually set by using the most recent polls, not designed to deliberately exclude them.)

Since the next debate is scheduled for November 14, that means candidates had to meet the polling threshold by six weeks before that — October 3. And that means it's impossible for Lessig to make the cut. "Unless we can time travel, there is no way that I will qualify," he said during his announcement.

If this account of events is accurate, then the DNC changed its rules in a really petty and ridiculous way, deliberately to exclude the one gadfly candidate remaining in the race, and limit its future debates to only Hillary Clinton, Bernie Sanders, and Martin O'Malley. (I've asked the DNC for comment on what happened, and will update this post if I hear back from them.)

But Lessig's campaign was going nowhere anyway

Yet Lessig can't blame all his campaign's problems on Democrats rigging the rules against him — because he just hasn't caught on.

Bernie Sanders, for instance, was little-known nationally at the beginning of this year. Yet he campaigned hard, impressed liberals and activists, and soared in polls. All this happened well before the debates — because Sanders's message, candidacy, and campaign turned out to be very appealing to Democrats.

By contrast, Lessig's idea of a "referendum presidency" — in which President Larry Lessig would promise to resign after signing a single major reform bill into law — was confusing and poorly thought out. It turns out that voters and activists care about a variety of issues, not just Lessig's reform proposal. Lessig ditched the resignation idea a few weeks ago, but to no avail.

Lessig's other problem is that Sanders has already locked up many of the anti-establishment liberals and activists who might have given Lessig a look. Indeed, a Reddit Ask Me Anything session Lessig hosted was filled with people who asked him why he wasn't just supporting Sanders, since he was also a longtime supporter of major campaign finance reform.

A debate appearance would have been a chance to change that, albeit not much of one. Still, Lessig should have gotten that chance.