WASHINGTON • A campaign without a ground game is one without loyal delegates.
This is a realisation Mr Donald Trump's team is coming to as it switches gears and starts focusing not only on winning states, but also making a play for delegates who will stay loyal to the candidate through the nominee-selection process.
These delegates are ultimately the ones who will select the next Republican nominee at the national convention in Cleveland in July.
Last weekend, the Trump campaign sent former presidential hopeful Ben Carson, who has endorsed Mr Trump, to North Dakota to rally the support of would-be delegates.
But not to be outdone, Texas Senator Ted Cruz personally made an appearance at the same state convention in Fargo.
Experts say Mr Cruz is already outmanoeuvring Mr Trump in this regard, racking up support from more delegates, even in states where the latter won the primary.
For example, in Louisiana, Mr Trump beat Mr Cruz by about 4 percentage points, and each candidate was allocated 18 delegates, according to party rules.
However, reports state that the Cruz campaign has likely swayed 10 extra delegates to join its camp. Five of these are unpledged delegates, who need not support a particular candidate, while the others are from former candidate Marco Rubio.
While Mr Trump has threatened to file a lawsuit, citing unfair Republican primary politics, it shows that his campaign is truly grasping at straws when it comes to organising supporters on the ground.
"Trump does not have the ground game that Cruz has, and what Cruz has done in Louisiana, he will try and do elsewhere," said professor of political science Mack Shelley from Iowa State University.
As candidates swing through the states during the primary election, they need to pick up 1,237 delegates to clinch the nomination. A possible loss in Wisconsin today might make it even harder for Mr Trump to hit that threshold.
Each state has different procedures by which they choose the delegates, but there are often state-level conventions, much like the one in North Dakota last weekend, where the national delegates are selected.
"Trump has got to make sure his supporters show up at all these different levels of conventions", so they can move on to the national convention, said Professor Shelley.
That in turn is important because "the convention rules are up to whoever is on the floor when the convention convenes", he added, and these rules can be set up to favour a certain candidate.
Delegate loyalty is also important, and especially so if Mr Trump does not get the 1,237 delegates needed to clinch the nomination.
Delegates are generally bound to a candidate during the first ballot at the national convention, but if the 1,237 threshold is not met, delegates can switch candidates in the following ballots.
This is where having a strong organisational structure can make a difference. "Cruz is much better organised," said Prof Shelley, pointing out that Mr Cruz had more than 1,000 precinct-level captains in Iowa, while Mr Trump had "very few".
These captains, he said, would "percolate up through the system and crack the whip at other people and keep them in line at the national convention".
Already, rumours abound that there are "several Trojan horses among the delegates", said Prof Shelley.
This means that on the day of the convention, they might be turncoats and vote for Mr Cruz after the first ballot, which is all the more reason Mr Trump's campaign has to work doubly hard to talk to supporters, educate them on the process and at the very least make sure they turn up.
"Trump supporters may be passionate, but they may not necessarily have a lot of experience or knowledge about the rules," said Prof Shelley.