Pedzisa mutsara unotevera: Achigara muChicago, Mosteller akabatsira pakuronga mushandirapamwe waObama wokutsvaga mutungamiri wenyika pawakanga uchangotanga muna February 2007. Achishanda muIowa, New Hampshire, nedzimwe nyika dzinokosha, akagadzira mitemo yakawanda nemiitiro zvaishandiswa nezvikwata zvaironga nzendo dzevaikwikwidza uye zviitiko. Akanga achibatanidzwa mukurongwa kwenzvimbo yenhaurirano dzokutanga dza2008 uye akaita basa reseneta pa
Gungano reDemocratic National muDenver. Mushure mokusarudzwa kwaObama, Mosteller akatamira kuWashington, D.C. uye akatanga muOval Office maawa mushure mokutanga. Mosteller akanga ari mumwe wemitezo yevashandi yakashanda kwenguva refu zvikurusa muhurumende. Vamwe vasingatauri mazita avo vakati "kana uchida [musangano] na2 mangwanani, unoenda kwaari". Muhurukuro ya2017, Obama akataura nezvaMosteller, "Ndiye maneja asingazununguki uye mutungamiri ane hunyanzvi hwekutsvaira zvinhu zvidiki". Mu "West Winging It", bhuku raakanyora rakabudiswa muna 2018, munyori anomuti "anotarisira kuchengetedza chiremerera muWest Wing yese".