title: Scatter plot in R with large overlap and 3000+ points
body: <p>I am making a scatter plot in R with ggplot2. I am comparing the fraction of votes Hillary and Bernie received in the primary and education level. There is a lot over overlap and way to many points. I tried to use transparency so I could see the overlap but it still looks bad.</p>
  
  <p><a href="https://i.stack.imgur.com/ygPp5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ygPp5.png" alt="My Graph"></a></p>
  
  <p>Code:</p>
  
  <pre><code>demanalyze &lt;- function(infocode, n = 1){
      infoname &lt;- filter(infolookup, column_name == infocode)$description
      infocolumn &lt;- as.vector(as.matrix(mydata[infocode]))
      ggplot(mydata) +
      aes(x = infocolumn) +
      ggtitle(infoname) +
      xlab(infoname) +
      ylab("Fraction of votes each canidate recieved") +
      xlab(infoname) +
      geom_point(aes(y = sanders_vote_fraction, colour = "Bernie Sanders")) +#, color = alpha("blue",0.02), size=I(1)) +
      stat_smooth(aes(y = sanders_vote_fraction), method = "lm", formula = y ~ poly(x, n), size = 1, color = "darkblue", se = F) +
      geom_point(aes(y = clinton_vote_fraction, colour = "Hillary Clinton")) +#, color = alpha("red",0.02), size=I(1)) +
      stat_smooth(aes(y = clinton_vote_fraction), method = "lm", formula = y ~ poly(x, n), size = 1, color = "darkred", se = F) +
      scale_colour_manual("", 
          values = c("Bernie Sanders" = alpha("blue",0.02), "Hillary Clinton" = alpha("red",0.02))
      ) +
      guides(colour = guide_legend(override.aes = list(alpha = 1)))
  }
  </code></pre>
  
  <p>What could I change to make the overlap areas look less messy?</p>