reporter: with her own reelection in november in little doubt and her presidential aspirations the subject of broad national speculation, warren has hit the road for other democrat candidates. i am so ready. reporter: including stacey abrams in georgia last week. meeting voters and building relationships. she s hardly alone among big name democrats. here is california senator kamala harris in ohio. truth is like the sun. it always comes up in the morning. i m loving iowa. reporter: that s new jersey senator cory booker behind the wheel of an rv, in the iowa corn fields, an awfully long way for new jersey, campaigning for a congressional candidate and maybe for himself too. booker joins a crowded field of mostly lesser-known democrats with national ambitions, popping up across the first presidential nominating state, more than two years before it nominates anybody. bernie sanders will make his