ANALYSIS: Now it's getting serious. Every state is a little more brutal and the result a little more critical.
There were two contests in two states on 20 February, with one party in each. Who says the Republicans and Democrats can't cooperate? They will now swap around, with the Republicans holding a caucus in Nevada on Tuesday while the Democrats have a primary in South Carolina next weekend.
While you wait with bated breath for those, here are a few thoughts on the Republican results in South Carolina and the Democrats' results in Nevada.
Republicans in South Carolina - the takeaways
Donald Trump won. Again. And, with only 32.5 percent of the vote, took every delegate. Unless it becomes a two-way race, surely he is now the favourite. Irish bookmaker Paddy Power certainly think so.
Mr Trump's support hasn't increased much beyond 30 percent but the opposition is still scattered across a wide field. There were still three establishment Republican candidates splitting South Carolina, without considering Ted Cruz or Ben Carson.
There are now only two, following Jeb Bush's withdrawal from the race, but even adding all their supporters together they only narrowly top him.
With Mr Bush gone, it's now likely Republican chairman Reince Priebus is gently suggesting to Ohio Governor John Kasich that he too should also step aside in favour of Marco Rubio.
He might, especially if the vice-presidential carrot is dangled. As a popular governor, Mr Kasich could hope to deliver an important swing state if he was on the general election ticket. It's got complicated enough now that Mr Preibus has started openly talking about a brokered convention.
Mr Rubio was the other South Carolina winner. He didn't get a single delegate but this was a win for him. It's a huge comeback from his New Hampshire result after the disastrous #rubioglitch debate performance. He is now the establishment's chosen champion. I bet they wish they had a stronger choice.
Coming third in South Carolina must have been devastating for Mr Cruz.
South Carolina is a religious, conservative state. It's sometimes said that they're still fighting the Civil War. Mr Cruz, a senator for Texas, is an evangelical candidate. His whole strategy has been based on winning big in the religious south, especially come Super Tuesday on 1 March.
On Saturday, I read that only utter humiliation would force Mr Bush out. By Sunday, the former Florida governor was gone. He'd come fourth in the state that prided itself on its support for previous Bushes.
He spent enormous amounts of money but still only narrowly beat Mr Kasich, who barely contested the state, and Mr Carson, who only seems to be in this for book sales and profile. Apparently nothing will buy success if you're just not the face the voters are looking for. His mother was correct after all.
So who'll get Mr Bush's supporters? A look at the second choices in a recent poll suggests they mostly favour the mainstream candidates, Mr Kasich and Mr Rubio, but some would also swing towards Mr Cruz and Mr Trump. The sample size makes this horribly invalid, statistically speaking, but it is interesting that they get spread so widely.
The other candidates don't just want Mr Bush's supporters, they want his donors.
Democrats in Nevada - the takeaways
The two remaining Democrat contenders relocated their contest to the wild west on Saturday.
Nevada is a more representative state than Iowa and New Hampshire, with both black and Latino populations. Caucuses are still new there and, with very few polls and little history to judge them by, it was anyone's guess who might win.
Hillary Clinton won Nevada in 2008, led by 29-year-old state campaign manager Robby Mook. He's now running her whole campaign, making him the first openly gay national campaign manager.
So this was something of a nervous homecoming but Mrs Clinton was in experienced hands.
Bernie Sanders had reduced his deficit in the Nevada polls enormously and was hopeful of continuing his rise with a win outside the northeast. In one of those odd American twists, it seems that local student Republicans were working hard for a Sanders win as well.
Ultimately, Mrs Clinton won, 52.7 percent to 47.2 percent, or 20 delegates to 15 (the Democrats tend to share delegates around more proportionally than the Republicans). Mrs Clinton now leads with 502 delegates to Mr Sanders' 70 (including super delegates), with a whopping 4191 as yet unallocated.
Mr Sanders initially spun this as a major step forward to inevitable victory but the numbers don't seem to bear that out. He also blamed low turn-out for his loss. 'If more people had voted for me, I would have won' may be a tautology but the logic is flawless.
According to entrance polling from CNN, Mr Sanders smashed Mrs Clinton among the youngest voters (82 percent to 14 percent), as he had in the earlier states, and those favouring honesty (82 percent to 12 percent).
Mrs Clinton crushed Mr Sanders - a senator for Vermont - amongst voters looking for electability (80 percent to 15 percent) and experience (92 percent to 8 percent).
White voters were pretty evenly split but who gained the Latino vote was more contentious. The entrance polls suggested Mr Sanders led Latinos 53 percent to 45 percent but Nate Cohn from the New York Times pointed out that, if that were so, Mrs Clinton shouldn't have won the heavily Latino east Las Vegas suburbs - and she did, handily.
Possibly, the Latino sample in the entrance poll just happened to be young.
Importantly for the ongoing contest, Mrs Clinton showed very strong support in the black community (76 percent to 22 percent), which will be a deciding factor in many of the upcoming races.
Current polls for next weekend's strongly black South Carolina contest show Mrs Clinton winning with a 20 point spread. From then until 15 March, there will be a slew of races with nearly 2000 delegates awarded and many of the contests are in states that are strongly black. The likely eventual winner should be clearer by then.
Because the Democrat state contest results remain proportional, this is looking increasingly like it could be a long race. Just a year ago, there was a presumption that Mrs Clinton was going to win all but uncontested - prompting much discussion about whether this inevitability was a good or bad thing.
Pundits wondered whether she might reach the general election untested, un-honed, and entirely ignored by the media; or whether the media might remain obsessed with private email servers and the Benghazi attack for lack of any real contest to cover.
Back then, Vox said: "Yes, Bernie Sanders is in the race. But he has so little support that his natural core constituency is pouring all its time and energy into trying to nudge Elizabeth Warren into the race."
Clearly he has beaten all expectations, possibly including his own. He has forced Mrs Clinton to hone her image, her message and her policies and to never take anything for granted.
But unless he manages to increase his black community support, and quickly, Mr Sanders is unlikely to win.
This is what primaries are meant to be: a testing ground for the real race that will start in July. You could argue that Mr Sanders' upstart campaign is the best thing that could have happened for Mrs Clinton; that if he didn't exist, she would have wished he did.
But she never would have wished it to be this close. The air miles, hotel beds and endless speeches must be starting to take a toll.
As if that all weren't bad enough, PBS reports that voters in Mr Sanders' childhood neighbourhood support Donald Trump.