Mostly nobodies who had no chance of winning though. Then again, that's what I thought about Trump.
Nah, a good chunk of the Republicans running were far more well known. 2008 runner-up Huckabee, 2012 runner-up Santorum, once 2012 front runner Perry, Chris Christie, Rand Paul, Scott Walker, Jeb!, Marco Rubio, Ted Cruz. Warren's the only one with that type of clout and she's still under 5% when "hypothetical" likelys are included.
Just because I like looking at these sorts of things...
RCP Averages
January 22, 2019: Biden 31, Sanders 12, Robert Francis 7, Harris 5, Booker 5, Warren 4, Bloomberg 4, Castro 4, Tulsi 4, Sherrod Brown 2, Gillibrand 1
January 22, 2015: Jeb! 17, Christie 11, Rand 9, Carson 8, Walker 8, Huckabee 8, Cruz 6, Rubio 5, Perry 4, Jindal 3, Kasich 2
June 22, 2015: Jeb! 13, Walker 12, Rubio 11, Carson 10, Huckabee 9, Rand 8, Cruz 7, Christie 5, Perry 4,
Trump 3, Fiorina 2, Santorum 2
August 6, 2015*:
Trump 24, Jeb! 13, Walker 10, Huckabee 7, Carson 6, Cruz 6, Rubio 5, Rand 5, Christie 4, Kasich 3
October 13, 2015**:
Trump 23, Carson 19, Rubio 10, Fiorina 8, Jeb! 7, Cruz 7, Kasich 3, Rand 3, Huckabee 3, Christie 3, Jindal 1
January 1, 2016:
Trump 36, Cruz 19, Rubio 12, Carson 9, Christie 5, Jeb! 4, Rand 3, Fiorina 2, Kasich 2
February 1, 2016 (Iowa):
Trump 36, Cruz 20, Rubio 10, Carson 7, Jeb! 5, Christie 3, Kasich 2, Rand 2, Huckabee 2
February 9, 2016 (NH):
Trump 30, Cruz 21, Rubio 18, Carson 8, Jeb! 4, Kasich 4, Christie 3, Fiorina 3
March 1, 2016 (Super Tuesday):
Trump 36, Cruz 20, Rubio 17, Carson 9, Kasich 9
March 15, 2016:
Trump 32, Cruz 26, Rubio 19, Kasich 18
*day of the first GOP debate
**day of the first DIMM debate