Does ground game matter? The 2016 presidential election might offer something like a definitive answer.

Campaigns’ get-out-the-vote efforts, from door knocking to phone banking to pamphleteering, have become an object of almost endless fetishization for the press in recent years. The Obama campaign in 2008 was hailed for its innovative turnout apparatus. Ted Cruz’s ability to identify and turn out his voters in this year’s GOP primaries was obsessively dissected, as was what one publication dubbed Marco Rubio’s “hollow” campaign.

But the importance of ground game, which has become the Republican National Committee’s singular focus this year, remains the subject of heated debate among political operatives. Some swear by it; others dismiss it as essentially a bunch of hocus-pocus. As one top Republican operative puts it: “A ground game means very little. It doesn’t mean nothing, it just means a lot less than people portray it as.” Because it’s difficult to know just how effective a campaign’s voter-contact efforts are, the George Washington University political scientist John Sides calls it one of the “great black boxes of campaigns.”