Former Vice President Joe Biden mounted an unsuccessful presidential campaign in 1988.

When incidents of plagiarism in campaign speeches and during his time in law school came to light, his campaign was soon suspended.

"My intent was not to deceive anyone,'' Biden wrote at the time. ''For if it were, I would not have been so blatant.''

Biden is mulling another run at president in 2020, of which an announcement could come this month.

Before Joe Biden was vice president during the Barack Obama administration, and before he bowed out of the 2008 presidential race, the longtime senator from Delaware unsuccessfully ran for the 1988 Democratic presidential nomination.

Incidents of plagiarism both on the campaign trail and during his time at the Syracuse University College of Law became some of the final issues that dogged Biden before he ultimately suspended his floundering campaign.

Read more: Joe Biden's long history in public life could come back to haunt him if he decides to run for president

During his failed 1988 run, Biden lifted portions of a speech by United Kingdom Labour MP and Margaret Thatcher challenger Neil Kinnock.

New York Times reporter Maureen Dowd reported on the fiasco in September 1987.

During an event at the Iowa State Fair, Biden mimicked entire portions of Kinnock's speech from earlier in the year. At one moment, Biden repeated the line that he was the first "in a thousand generations" to graduate from college, gesturing to his wife in the exact same way Kinnock did, while also saying the same line about her education and lineage.

Biden would later acknowledge that he in fact did have relatives who attended college, directly contrasting the Kinnock lines.

As Dowd reported, Biden's staffers were defensive about the allegations of blatant plagiarism. Nevertheless, Biden dropped out of the race by the end of the month.

According to another 1987 article in The Times, Biden acknowledged plagiarizing a law review journal for a paper during law school, and asked school administrators not to be expelled. But Biden also said he made a mistake in the citation process.

"My intent was not to deceive anyone,'' Biden wrote at the time. ''For if it were, I would not have been so blatant.''

The scandal erupted at the same time Biden was chairman of the Senate Judiciary Committee and was overseeing the infamously partisan confirmation process of the failed-Supreme Court nominee Robert Bork.

Biden's plagiarism became a hot campaign issue which his 1988 Democratic rival, Massachusetts Gov. Michael Dukakis, used in a video attack ad that was passed around to several media outlets, according to a Washington Post article in 1987.

At the time, Biden dismissed the distribution of the video by other campaigns as dirty politics.

"Look, I'm a big boy,'' he said. ''I've been in politics for 15 years. This is not my style. If they want to do it this way, so be it."

Dukakis — who would go on to win the nomination but lose the general election to the late-President George HW Bush — ultimately fired his political director Paul Tully and campaign manager John Sasso over the ad.

In a telling moment demonstrating how much more collegial primary battles were just three decades ago, Dukakis even held a news conference where he apologized to Biden, "his family and his friends for what happened and for the involvement of my campaign in this whole situation," The Times reported in 1987.

Biden reiterated that he was wrong, but did not deliberately intend to plagiarize while in law school.

"I was wrong, but I was not malevolent in any way,'' he said. ''I did not intentionally move to mislead anybody. And I didn't. To this day I didn't."

''When I was at Syracuse,'' Biden added, ''I was married, I was in law school, I wore sports coats. You're looking at a middle-class guy. I am who I am. I'm not big on flak jackets and tie-dyed shirts. You know, that's not me.''