Comment: I'm not following your calculations..

π -> the probability of a success on any one observation, so 4 states won out of 41 total (4/41)
n -> # of remaining states
x -> # of successes

π = 4/41 ~ .097561
n = 9

For x=0 successes (probability of winning 0 out of 9 remaining states)
=BINOM.DIST(0, 9, 0.098, 1) = 39.70%

For x=1 (1 out of 9 remaining states), it is 38.63%
For the cumulative probability of winning 1 or 2 or 3 or 4 etc. up to all 9, it would be 60.30% (100%-39.70%)

So the probability of winning at least one of the remaining states, assuming the % of historic state wins for RP this primary season remains consistent, is about 60%. Still pretty high but this doesn't take into account the independent variables like participation, establishment shenanigans, etc.

You may have forgotten to subtract the probability of 0 wins when you did the cumulative probability.