What's the worst major party in the world?

[Stranger in a strange land]

Sinn Fein are objectively NOT the worst party in the world.

Sinn Fein is pretty bad, but Golden Dawn, Jobbik, the PVV, and the FPO are all worse. Also, how is Sinn Fein objectively any worse than the DUP? There's also the BNP, but it probably doesn't qualify as a "major" party.

Are we not counting parties that win >99% in fraudulent elections? If not, then how was nobody suggested the Workers' Party of Korea?

I think we're supposed to assume that this only includes legitimately democratic elections.

Perhaps it would be one in a country that only barely qualifies as a democracy. Maybe some Indian party.

None of the Indian parties are great, but none of them are as bad as the European Far-Right parties.

Are we not counting parties that win >99% in fraudulent elections? If not, then how was nobody suggested the Workers' Party of Korea?

I think we're supposed to assume that this only includes legitimately democratic elections.

Parties the Worker's Party of Korea or the Syrian Ba'ath party don't count because there's basically no way they can lose "elections."

Though speaking of which, are there any unreformed Stalinist parties that hold seats won in free and fair elections?

[Stranger in a strange land]

I can't think of any major party in the developed world that is worse than the U.S. Republican Party. 

The GOP has some pretty vile elements and has been on a long downward spiral for some time, but how is it worse than actual fascist parties like Jobbik and Golden Dawn?

[Stranger in a strange land]

It's hard to argue against the answer being Golden Dawn, with Jobbik maybe not far behind.

With a stricter definition of "major party", I'm very tempted to say the Republicans, but there are some other convincing candidates mentioned in this thread, such as Fidesz and Berlusconi's lot.  I'd also suggest that the Swiss People's Party deserve a mention.

Fidesz is definitely worse than the GOP, but only by a depressingly small amount. Then again, I don't think Fidesz has ever intentionally damaged Hungary's credit rating as a bargaining tactic to force cuts in welfare for poor people to fund tax cuts for the extremely wealthy.

Judging by how various Republican state parties try to restrict the franchise by stringent voting requirements that the poor can't meet, gerrymandering, proposals to allocate electoral votes for president via gerrymandered congressional districts, and even outright voter intimidation, I'd say that Fidesz isn't significantly worse than the GOP, and sad to say, it's probably better than some of the Beck/Bachmann elements. Still not as bad as Golden Dawn and Jobbik though.

Off the top of my head:

Parties that have formed/have a shot at forming government:
BJP
Sinn Fein

The FPO has been in government, and the PVV has been in negotiations to form a government, meaning that it probably has a shot at being in government at some point.

[Stranger in a strange land]

1. Don't even claim to be democracies (Saudi Arabia, Swaziland, China)

China claims to be democracy.

China may pay lip service to "grassroots democracy", "people's democracy", "people's democratic dictatorship", or whatever term happens to be in vogue at the moment, but it's leaders and their sycophants are pretty openly contemptuous of democracy.