Trump's campaign lacks one essential tool

He has a commanding lead in the polls, but Donald Trump is the only Republican presidential candidate who hasn’t purchased a database of voter information, which political campaigns use to target supporters and mobilize them on election day.

Modern campaigns also rely on voter files to plan everything from advertising to events, and accurate information is particularly key in the early state of Iowa, where voters will select a candidate in January through a complicated caucus process that gathers individuals in a room to make a group decision. Meticulous organization is seen as the key to victory.

But Trump’s campaign hadn’t purchased any voter information as of the end of September, according to financial disclosures analyzed by Quartz, and his campaign confirms that he is not using the national Republican party’s voter file.

Voter databases are created from the electoral rolls of registered voters in a given county, but those records quickly become outdated as people move or pass away. They also don’t reflect which registered voters actually vote on a regular basis. Campaigns constantly update this information by canvassing neighborhoods and calling voters, then share it with national party organizations or private companies who attempt the keep the information as current and usable as possible.