Worst should have been competitive House candidate.

[136or142]

Off the top of my head and maybe it's because I live in the neighboring province, I'd have to go with Jim Moeller in Washington State.  He's the Washington State House Speaker Pro Tem and, while he's running against a popular Republican, she did win in the wave Republican year of 2014 with just over 60% of the vote, so he could have at least tried to have made it close.

At the Congressional level in Washington State, except for the two Democrats running in the Seattle based district of retiring (I'd say his brain retired years ago, but that's another matter) Jim McDermott, there really isn't anything else that's competitive.  And yet, as of September 30, he still hadn't even raised $100,000.

[publicunofficial]

Moeller is kind of a kook, and way too liberal for that district. I never had any hope.

If we're talking bad WA congressional candidates, Tony Ventrella is a better answer.

[Figueira]

Paul Babeu was a very bad choice for Republicans in AZ-1.

[Heisenberg]

Paul Babeu was a very bad choice for Republicans in AZ-1.

Beat me to the punch.

[136or142]

Moeller is kind of a kook, and way too liberal for that district. I never had any hope.

If we're talking bad WA congressional candidates, Tony Ventrella is a better answer.

Tony Ventrella kind of did it too himself though by refusing most donations.

[PAK Man]

Jack Martins in NY-03 seemed really hyped up, with the GOP even pretty much clearing the primary for him (Dems had a very competitive primary). Yet polling has shown Tom Suozzi with a pretty good lead and national Republicans have pretty much pulled out of the race.

Monica Vernon in IA-01 is a hyped-up candidate for the Dems who seems to be doing poorly. This is a district Obama won with 56%, and yet most polling has shown Blum with a slight lead. An Iowa friend of mine who I talk politics with kind of groaned when she jumped into the race (he didn't like Pat Murphy either, partially for fumbling a winnable race in 2014). Though I don't know if that's a reflection on Vernon or the fact that Clinton isn't doing very well in Iowa.

[Young Conservative]

Paul Babeu was a very bad choice for Republicans in AZ-1.

Beat me to the punch.

[Figueira]

I thought of another one: the consensus on Atlas seems to be that Emily Cain is a bad candidate. She still could win anyway though, since ME-2 isn't heavily Trump-favored like it was earlier in the race. Staying in New England, the Republicans should have primaried Frank Guinta if they wanted to keep NH-1.

[publicunofficial]

Scott Jones in CA-07
Emilio Huerta in CA-21
Shaun Brown in VA-02

[Pessimistic Antineutrino]

Don Bacon in NE-2 should be doing better considering the district's Republican lean, though it could just be because Ashford is a strong incumbent.

Danny Tarkanian in NV-3 and Jason Lewis in MN-2 both seem to have been bad choices as well.

[PAK Man]

Shaun Brown in VA-02

Was he ever considered competitive? National Dems never seemed to take interest in this race. I consider VA-02 more of a recruitment failure than a bad competitive candidate.

[Zioneer]

I would agree with Don Bacon in NE-2, Danny Tarkanian in NV-3, Jason Lewis in MN-2, Paul Babeu in AZ-1, and a couple of others that I can't remember at the moment.

I guess Charlene Albarran in UT-2 is a lackluster candidate, though considering how Republican the district is, I'm not surprised that we've got a lackluster candidate. Oh and Stephen Tyron in UT-3, who also also challenged Jason Chaffetz in 2014 as an independent... and got 1% of the vote.

[PAK Man]

To be fair to the GOP, neither Babeu, Lewis or Tarkanian was the actual candidate they wanted.

[Heisenberg]

I would agree with Don Bacon in NE-2, Danny Tarkanian in NV-3, Jason Lewis in MN-2, Paul Babeu in AZ-1, and a couple of others that I can't remember at the moment.

I guess Charlene Albarran in UT-2 is a lackluster candidate, though considering how Republican the district is, I'm not surprised that we've got a lackluster candidate. Oh and Stephen Tyron in UT-3, who also also challenged Jason Chaffetz in 2014 as an independent... and got 1% of the vote.

Bacon? I mean he's not the perfect candidate, but the NRCC definitely backed him over the other, more conservative candidate. Democrats even helped try to bolster Bacon's opponent (can't remember his name) because Ashford would have had an easier general election with the other guy. I agree with the others you listed.
Other primary flops:
NH-01 and 02: Neither were winnable, but in both, the more unelectable candidates won.
NY-22: Tenney's more moderate opponent would've been in a much better position
MI-01: Casperson was he better candidate, and the establishment pick
MI-10: Pavlov, see above
FL-18: Negron, see above

[Kingpoleon]

Democratic:
IA-4: Christie Vilsack
IL-12: Sheila Simon
IL-14: Frank Mautino

Republican:
MN-2: Pat Garofalo
MN-8: Chip Cravaack
NV-3: James B. Gibson

[publicunofficial]

Democratic:
IA-4: Christie Vilsack
IL-12: Sheila Simon
IL-14: Frank Mautino

Republican:
MN-2: Pat Garofalo
MN-8: Chip Cravaack
NV-3: James B. Gibson

Ah, another "Kingpoleon checks Wikipedia to find the most notable politician living in a district, without doing any other research" post.

Chip Cravaack no longer lives in Minnesota, and now teaches History in New Hampshire.

[PAK Man]

IA-4: Christie Vilsack

Myself and a few other Iowans thought she ran a really bad campaign. She had a couple ads that were pretty laughable. Plus, as someone who lives in IA-04, I can tell you that King isn't going anywhere. He does a lot of work for the farmers and they're either willing to look the other way on his offensive comments or they think the "liberal media" is making them up.

Check this out:
http://iowastartingline.com/2016/07/24/why-western-iowa-keeps-voting-for-steve-king/

[Kingpoleon]

Democratic:
IA-4: Christie Vilsack
IL-12: Sheila Simon
IL-14: Frank Mautino

Republican:
MN-2: Pat Garofalo
MN-8: Chip Cravaack
NV-3: James B. Gibson

Ah, another "Kingpoleon checks Wikipedia to make sure the politician he has in mind lives in the right district" post.

Chip Cravaack no longer lives in Minnesota, and now teaches History in New Hampshire.

FTFY.

[Heisenberg]

Democratic:
IA-4: Christie Vilsack
IL-12: Sheila Simon
IL-14: Frank Mautino

Republican:
MN-2: Pat Garofalo
MN-8: Chip Cravaack
NV-3: James B. Gibson

Ah, another "Kingpoleon checks Wikipedia to make sure the politician he has in mind lives in the right district" post.

Chip Cravaack no longer lives in Minnesota, and now teaches History in New Hampshire.

FTFY.

Did Cravaack move back to Minnesota?