Republican and Democrat presidential candidates will undergo their biggest day of judgement in the build up to the 2016 Presidential election so far today, with a dozen states and one territory voting on one day, in the first taste of a national test for candidates of both colours.
Republican candidates have the opportunity to win almost half of the number they need for the overall nomination.
It looks like Donald Trump is in store for twitter.com/nypost/status/703585398186975235/photo/1?ref_src=twsrc%5Etfw">another "yuuuge" day. The question for Trump may not be if he wins, but how many states he wins, with his competitor John Kasich saying he could win all the states.
The Southern states will provide Trump with a further opportunity to close in on the nomination, as he typically fares better there, as well as in the industrial north east, according to the New York Times.
But Ted Cruz should pull off victory in his home state of Texas. It’s a must win state if Cruz wants to mount a challenge to Trump, and could represent a watershed moment in his campaign. It's also a huge state to win, given the number of delegates it sends to the national convention.
In Colorado the 37 Republican delegates will not have to pledge themselves to a candidate – meaning the delegates will not be bound to anyone at the national convention in July, and will be free agents. Only one poll has been taken here, putting Carson in the lead.
But given the few-and-far-between polling in Colorado – as well as Arkansas, Vermont, Minnesota and Alaska – the numbers should be taken with caution. In fact, in Arkansas, though Trump is ahead as an average, the most recent poll put Cruz in the lead.
Cruz's challenge is to garner sufficient support from conservative and religious voters, while Marco Rubio may struggle tomorrow but find he has more of a chance later in the year as primaries hit more moderate states - if he can hang in there.
Alaska has also only had one poll this year, which put Trump ahead, but there's a huge amount of uncertainty in this state.
There’s the opportunity to bag close to a third of the delegates needed for the Democrat nomination, and Hillary Clinton looks set to run away with it.
She should win the southern states comfortably, especially with a large number of black voters which have backed her so far (and backed her rival, one Barack Obama, back in 2008).
Her rival Bernie Sanders looks dead-set to win just one state: Vermont, in his native north east. Still, with the state claiming one of the smallest populations in the country, it only has 26 delegates on offer.
But he could provide an upset in states outside of the south. These are mostly white states, with a large number liberal or working class voters.
Massachusetts will be a tight state for Clinton and Sanders, where the gap between them in the polls is small.
In Minnesota, Colorado and Alabama polling has been sparse, so there could be a discrepancy between the polling and the outcomes.
Democrat delegates will also be sent from American Samoa, a US territory. It only has 55,000 residents, which can't vote in the election later this year, but can send their 10 delegates.
Above all, tomorrow has the potential to narrow the field - for the Republicans, anyway.