When we come to look back on the general election campaign, this week may be remembered as the week the wheels came off for two of the parties hoping to break into the political mainstream in 2015.
Green Party leader Natalie Bennett gave the election campaign's first real car crash interview on LBC on Tuesday (though being the Greens it was probably a hybrid car crash, so at least it had lower emissions than other political car crashes).
In the face of fairly friendly questioning from LBC presenter Nick Ferrari, Bennett fell apart. Ferrari presented Bennett with a green light opportunity to announce her party’s election promises and Bennett went about it with all the cool, calm composure of somebody falling down a flight of stairs.
Bennett's facts and figures sounded made up and certainly didn't add up. Her delivery was panicked and faltering. The low point - not easy to single out in one of the most horrible political interviews in living memory - was the briefest of moments, the intonation on a single word.
At one point Bennett mentioned a number "2.7", then paused... then paused a little longer... before adding "billion" with all the confidence of somebody who wasn't even sure if "billion" is a real word, let alone the word she was looking for.
Bennett tried to blame her abysmal performance on having a cold. Even the excuse was a bit rubbish. But she isn't alone in offering half-baked excuses to cover up for half-baked ideas and awful interviews. At the opposite end of the political and ethical spectrum, UKIP have a remarkable record of trying to blame their racist and homophobic outbursts on everything from tiredness to medication.
And UKIP were back in the spotlight this week at a time when the party's star has undoubtedly been on the wane. BBC2 programme Meet The Ukippers introduced us to the members and activists at the heart of the party.
During the programme we met an array of characters and heard many times how UKIP definitely, definitely, definitely, definitely isn't racist.
In fact Nigel Farage went to lengths to explain that this perception of UKIP being racist is all the fault of the media. And definitely not the fault of the UKIP members who say racist things.
At the centre of the programme was UKIP's South Thanet press officer, Liz Langton-Way, who actually seemed surprised to discover some UKIP members are racist.
It's always the ones you least expect, eh Liz.
The programme showed how Langton-Way, the proprietor of Thanet's first dog hotel, likes to surround herself with clowns (possibly explaining why she chose to work for UKIP). Her luckless task, she explained, was to ensure UKIP generates only positive headlines and keeps clear of scandal.
Her slick media operation certainly impressed one Twitter user:
Didn't used to take UKIP seriously but now I know they run everything from a dog hotel full of porcelain clowns I'm torn #MeetTheUkippers— GusTheFox (@GusTheFox) February 22, 2015
Remarkably, Langton-Way made her impossible job appear even more difficult than it surely should be. At one point she was sat on a sofa having a natter and stroking her dogs while a party member made a series of controversial comments on camera. It's hard to believe that was advice she found in the How To Be A Press Officer handbook. But Langton-Way certainly wasn't helped by party members such as Janice Atkinson MEP referring to an Asian constituent as a "Ting Tong".
UKIP councillor Rozanne Duncan also didn't help matters when discussing on camera the fact that she doesn't like "negroes". Duncan doesn't know why she doesn't like "negroes". She just doesn't like "them".
But she's definitely not racist. She was adamant about that, though not everybody was convinced:
What was so very UKIP about Rozanne's racism is the bafflement that anyone could possibly consider it racist #MeetTheUkippers— David Baddiel (@Baddiel) February 22, 2015
Then we met Martyn Heale, chairman of UKIP in Thanet South, who appeared utterly baffled as to why people would find his past membership of the National Front of interest.
"For Christ's sake, I was never a member of the Gestapo," said Heale, setting a remarkably low benchmark for what UKIP considers respectable.
Of course, not having been in the Gestapo isn't their only criteria. Heale pointed out he also "was not a member of the Stasi" and has never served any time in prison.
What a catch.
The troubles of the Green Party and UKIP alike will inevitably do little to deter their hard core of support.
If anything, the accusations of racism which follow UKIP wherever they go have probably been an effective recruitment tool for the party. Conversely, Green Party supporters are probably all too nice to be deterred by Bennett's abysmal performance or think any less of her because of it. Even now they are probably sending her some echinacea for her cold.
But damage will surely have been done to their chances of recruiting supporters outside their hard core - the floating voters who were hoping a challenger party might offer a credible alternative at the polls.