One didn't cause the other, but several long-running narratives exploded together in a way that ultimately and in hindsight sent Hillary Clinton's campaign floundering and gave Donald Trump's new hope in the waning days of the election.

There is an undeniable through-line between the investigation into Weiner's proclivity to sending lewd message via text, on this occasion victimizing a teenage student, and Trump's 2016 victory.

Look at this timeline:

January 2016

Underage girl allegedly reaches out to Weiner on Twitter and he starts online relationship with her, according to the Daily Mail. Court documents released Friday suggest the relationship carried on online until March and that Weiner knew the minor was 15 and that he transferred sexually explicit material to her.

July 5

FBI Director James Comey announces at a bombshell press conference there is not enough evidence to seek charges against either Clinton or her staff for their handling of classified information during her time as secretary of state. He upbraids the candidate as irresponsible , but the campaign hopes this puts a lingering issue about her trustworthiness behind them.

September 22

JUST WATCHED CNN's September report: FBI, NYPD investigating Weiner underage sexting allegation Replay More Videos ... MUST WATCH CNN's September report: FBI, NYPD investigating Weiner underage sexting allegation 02:13

CNN reports that then-US Attorney Preet Bharara in New York is investigating allegations first reported in the Daily Mail, that Weiner had carried on a sexting relationship with the minor.

October 28

JUST WATCHED CNN's late October report: FBI reviewing new Clinton emails Replay More Videos ... MUST WATCH CNN's late October report: FBI reviewing new Clinton emails 03:04

Comey tells Congress in a letter that new information from a separate investigation, which we later learn to be the one involving Weiner, has led them to re-start the inquiry into Clinton's treatment of classified information as secretary of state. Clinton has since said this letter cost her the election.

October 30

FBI obtains search warrant for Weiner's computer in order to look for information related to Clinton's time as secretary of state. Comey later testifies that the computer contains messages forwarded by Huma Abedin, a top Clinton aide and Weiner's husband. Abedin forwarded messages for reasons as mundane as to print them. None of the information on the computer is marked as classified. But it doesn't matter since this issue is again front and center.

November 6

JUST WATCHED FBI clears Clinton in email probe Replay More Videos ... MUST WATCH FBI clears Clinton in email probe 01:32

FBI tells Congress -- two days before election day! -- that the new information does not change their determination that neither Clinton nor her staff should face charges for their handling of classified information.

November 8

JUST WATCHED Trump just before Election Day: Clinton is guilty and she knows it Replay More Videos ... MUST WATCH Trump just before Election Day: Clinton is guilty and she knows it 01:28

Trump wins the presidential election after spending the campaign maligning Clinton as "crooked" and saying she should be in jail.

This is obviously reductive logic. Clinton could have never hired Abedin. She could have not made the decision to keep emails on a private email server. She could have been vice president instead of secretary of state. Comey could have kept quiet about the investigation until after the election.

There's an unending rabbit hole of what-ifs.

But the crux of what created the last-minute decision for Comey was the September allegation against Weiner and the US Attorney's ensuing investigation.

There are many reasons Trump won the election. He tapped into white working class frustration that helped him pull the Rust Belt foundation out of Democrats' political coalition, for instance.

Hillary Clinton was a candidate who inspired apathy among the rest of the Democratic coalition.

You could write a book -- people already have! -- about what happened that led to her loss and Trump's victory.

But Clinton herself has blamed Comey for costing her the election.

"If the election had been on October 27, I would be your president," she recently told CNN's Christiane Amanpour.

Weiner pleaded guilty Friday to transferring obscene material to a minor. He was released on bail until his sentencing and he'll have to register as a sex offender. The crime carries a maximum penalty of ten years in prison, although it is possible he could not serve any jail time.

All that is really besides the point for the vast majority of Americans. What matters is that either you believe Comey's October surprise swayed the election or you don't. Hillary Clinton does.

And there's no real way to look at the chain reaction of decisions and events that led to Comey's letter to Congress about Clinton's treatment of classified information other than it began with Anthony Weiner's sexting.