scale_y_discrete add label from vector

Question

does anyone know how to remove the word "name_id" on the y-axis?

Here is the code:

library(lubridate)
fouryears <-   # set start y-m-d
  make_date(seq(year(min(presidential$start)),
                year(max(presidential$end)),
                by = 4), 
            1, 1)
library(forcats)
library(stringr)
presidential %>%
  mutate(   # create president name and seq.
    id = 33 + row_number(),
    name_id = fct_inorder(str_c(name, " (", id, ")"))) %>%
  ggplot(aes(start, name_id, colour = party)) + 
    geom_point() +
    geom_segment(aes(xend = end, yend = name_id)) +   # draw duration line
    scale_colour_manual("Party",   # set color for party
                        values = c(Republican = "red", Democratic = "blue")) +
    scale_y_discrete("name_id") + # not use label from 'aes' above
    scale_x_date(NULL,  # not use label from 'aes' above
                 breaks = presidential$start, # set break points
                 date_labels = "'%y",  # show `yy for the year
                 minor_breaks = fouryears) +  # tick every 4 years
    ggtitle("Terms of US Presdients",
            subtitle = "Roosevelth (34th) to Obama (44th)"
    ) +
    theme(
      panel.grid.minor = element_blank(), 
      axis.ticks.y = element_blank()
    )

I assume it must be an argument in scale_y_discrete(). I tried "name", "label" but no success.