THEY THOUGHT THE SCIENCE WAS SETTLED: How Analytical Models Failed Clinton: Her campaign was so confident in its data that it opted not to do tracking polls in states that decided the election.

In 2004 the Howard Dean, George W. Bush-Dick Cheney, and John Kerry-John Ed­wards pres­id­en­tial cam­paigns ad­vanced the uses of data to con­tact voters, but it was the 2008 cam­paign of Barack Obama that took ana­lyt­ics to a whole new level. The in­fatu­ation with ana­lyt­ics after Obama’s reelec­tion in 2012 promp­ted some of his op­er­at­ives to say they didn’t need tra­di­tion­al polling any­more.

When Hil­lary Clin­ton began put­ting to­geth­er her 2016 cam­paign, she brought on board many Obama vet­er­ans, go­ing all in for the new tech­no­logy. Don­ald Trump’s gen­er­al-elec­tion cam­paign also em­ployed ana­lyt­ics, though how soph­ist­ic­ated and im­port­ant it was in his vic­tory is a mat­ter of con­sid­er­able de­bate. House and Sen­ate cam­paign com­mit­tees and su­per-PACs also used ana­lyt­ics to vary­ing de­grees.

The re­li­ance, or per­haps over­re­li­ance on ana­lyt­ics, may be one of the factors con­trib­ut­ing to Clin­ton’s sur­prise de­feat. The Clin­ton team was so con­fid­ent in its ana­lyt­ic­al mod­els that it op­ted not to con­duct track­ing polls in a num­ber of states dur­ing the last month of the cam­paign. As a con­sequence, de­teri­or­at­ing sup­port in states such as Michigan and Wis­con­sin fell be­low the radar screen, slip­page that that tra­di­tion­al track­ing polls would have cer­tainly caught.

Ac­cord­ing to Kantar Me­dia/CMAG data, the Clin­ton cam­paign did not go on the air with tele­vi­sion ads in Wis­con­sin un­til the weeks of Oct. 25 and Nov. 1, spend­ing in the end just $2.6 mil­lion. Su­per PACs back­ing Clin­ton didn’t air ads in Wis­con­sin un­til the last week of the cam­paign. In Michigan, aside from a tiny $16,000 buy by the cam­paign and a party com­mit­tee the week of Oct. 25, the Clin­ton cam­paign and its al­lied groups didn’t con­duct a con­cer­ted ad­vert­ising ef­fort un­til a week be­fore the elec­tion.

In fact, the Clin­ton cam­paign spent more money on tele­vi­sion ad­vert­ising in Ari­zona, Geor­gia, and the Omaha, Neb­raska mar­kets than in Michigan and Wis­con­sin com­bined.