ggplot2 with side by side and proportional fill - r

Question

I have data that looks like this:
My goal is to have a barplot grid as follows: Each plot will be specific to 1 race_ethnicity group. The x-axis in each plot will be the different age_bin groups. For each age_bin, there will be two bars: 1 for men, and 1 for women. For each bar, I want it to be filled with the proportion of Likely/(Unlikely + Likely). Preferably, each bar would have a height of 1 and a line cut through it so Likely% of that bar is one color with a label. This is what I currently have:
I am running into issues with 1) using a predefined proportion as the fill, and 2) having two different "fills" (one for biological sex, one for the predefined proportion.
Thanks to anyone who can help with this. My code is currently the following:
ggplot(data=who_votes_data, aes(x=age_bin,y=1, fill=gender)) +
geom_bar(stat='identity',aes(fill = gender), position = position_dodge2()) +
facet_wrap(~race_ethnicity, nrow = 2, scales = "free") +
geom_text(aes(label=paste0(sprintf("%1.1f", prop*100),"%"), y=prop),
colour="white") +
labs(x = expression("Age Group"), y= ("Prortion of Likely Voters"),
title = "Proportion of Likely Voters Across Age Groups, Race/Ethnicity, and Sex",
caption="Figure 1") + theme(plot.caption = element_text(hjust = 0.5, vjust = -0.5, size = 18))
https://docs.google.com/spreadsheets/d/1a7433iwXNSwcuXDJOvqsxNDN6oaYULVlyw22E41JROU/edit?usp=sharing
Updated Code:
library(tidyverse)
library(ggplot2)
df<- read.csv("samplevotes.csv")
df %>%
group_by(race_ethnicity, age_bin, gender) %>%
summarise(Likely = sum(Likely),
Unlikely = sum(Unlikely),
proportion = Likely/(Likely+Unlikely)) %>% ungroup() %>%
ggplot(aes(x = age_bin, y = proportion, fill = gender)) +
geom_bar(stat = "identity", position = "dodge") +
facet_wrap(~race_ethnicity, nrow = 2) +
geom_text(aes(label=paste0(sprintf("%1.1f", proportion*100),"%"), y=proportion), position = position_dodge(width = 1), colour="Black", size = 2.2) +
labs(x = expression("Age Group"), y= ("Proportion of Likely Voters"), title = "Proportion of Likely Voters Across Age Groups, Race/Ethnicity, and Sex", caption="Figure 1") +
theme(plot.caption = element_text(hjust = 0.5, vjust = -0.5, size = 18))

Answer 1

Here is the code I would use. I did make some changes based on the way the data was combined.
df %>%
group_by(race_ethnicity, age_bin, gender) %>%
summarise(Likely = sum(Likely),
Unlikely = sum(Unlikely),
proportion = Likely/(Likely+Unlikely)) %>% ungroup() %>%
ggplot(aes(x = age_bin, y = proportion, fill = gender)) +
geom_bar(stat = "identity", position = "dodge") +
facet_wrap(~race_ethnicity, nrow = 2) +
geom_text(aes(label=paste0(sprintf("%1.1f", proportion*100),"%"), y=proportion), position = position_dodge(width = 1), colour="Black", size = 2.2) +
labs(x = expression("Age Group"), y= ("Proportion of Likely Voters"), title = "Proportion of Likely Voters Across Age Groups, Race/Ethnicity, and Sex", caption="Figure 1") +
theme(plot.caption = element_text(hjust = 0.5, vjust = -0.5, size = 18))
Here is what it looks like