How does that equate to "open borders"?
No one's ever denied more people are trying to enter. But the GOP seems to constantly calling for securing the southern border in response to the "open border policy" supposedly espoused by Democrats, which implies they're just letting everyone in.
Your chart shows the opposite. The great majority of migrants at the people are encountering border patrols, local law enforcement, etc., and from there are either being turned away, entered into asylum process, detained at least temporarily etc.
Again, I'm all for comprehensive immigration reform. I've yet to see any sign that Republicans are.