Ukip fever is upon us. It rampages through our television studios, it rides our airwaves, it plasters up our street corners.
Ukip fever is the new national disease and right now everybody is getting a dose.
The European elections next week will see Ukip fever reach its peak. Although already widely suffering from the disease, Westminster is likely to sink into the depths of a full scale Ukip epidemic.
If as expected, Nigel Farage's party wins the most seats, then the demands will immediately begin for the three main parties to "react". This reaction is unlikely to be pretty. Already manoeuvres are on within the Labour party for Ed Miliband to take a much more anti-immigration stance.
Of course Labour MPs and activists can't come out and say this. Nobody wants to be seen saying "look Ed, you just need to duff up the Poles and Romanians a bit more".
So instead we will see a slew of articles and blog posts calling on Miliband to understand the 'concerns' of Ukip voters.
So what are these concerns and is it possible for any party to meet them? Let's look at the evidence.
A poll out this week found that 87% of Ukip voters want to stop all immigration to the UK.
Not some immigration. Not certain people from certain countries. No, all immigration. All of it. They basically want a big gate at Dover, with Nigel Farage holding the only key.
Asked what to do with those immigrants already here and their families, 51% said that all of them should leave, even those who were born here. Yes even those who were born here. Even those who aren't actually immigrants.
Now it's hard to see what any party could possibly do to meet these concerns. Save from turning the UK into a giant prison state, there is always going to be a certain amount of migration in and out of the country.
And it's even harder to see what Ed Miliband, a liberal son of two immigrants could begin to do to address those concerns.
Of course one way to address those concerns would be to explain why they are unfounded. To explain why it would be a terrible thing for the country to close it's doors to all immigrants and to deport the millions of people already living here to countries many of them have never even been to.
To explain that stopping immigration would cripple our hospitals, cripple our schools and massively increase our national debt.
This was the approach once taken by many within Labour, the Liberal Democrats and even the Conservatives. But as the vote shares of the three main parties has shrunk, so too has their confidence to make the positive case for immigration and immigrants in the UK.
It is now only the Green Party and a few other left-wing parties and groups that are now willing to make this case. The effect of this is already clear.
Polling out this week found that immigration is now the main concern of voters in the UK, above even the economy.
Now this is not a response to some great new wave of immigration to the UK. As new figures showed this week, Ukip's warnings of 29 million Bulgarians and Romanians flooding into the UK were totally unfounded. In reality, 4000 actually left when border restrictions were lifted in January.
Nor is it a reflection of economic conditions. Other figures out this week showed that unemployment is now at recent historical lows.
No, the rise in concern over immigration has little to do with facts and everything to do with the sickness that Ukip fever has spread across the country.
As I wrote a couple of weeks ago, Ukip is undoubtedly a racist party, with racist candidates and a racist agenda. As Farage's remarkable interview with LBC today so brilliantly showed, this racism extends right from the most obscure activist to the door of Nigel Farage.
But while it is important to highlight this racism, it is also important to realise that there is a price to pay. For every bigoted Ukip statement that is plastered across our papers, the country is nudged just that little bit further to the right.
Whereas it was once taboo for a party leader to say they were "uncomfortable" hearing foreign voices on a train, it is no longer. And whereas it was once unthinkable to hear a politician telling voters to be scared of foreigners moving in next door, it is now a regular occurrence.
The rise of Ukip is slowly but surely moving the terms of debate in the country and it is moving it in a direction that should worry everyone who thought Britain was a tolerant and enlightened place to live in.
The fight can still be won, but first the three main parties must step into the ring to fight it. Right now, they're heading for the exit.