I was hoping this wouldn't happen, but it's something most of us figured was a real possibility when Trump was elected. Barring something left-field, a judge should be nominated and confirmed this year since Republicans control the Senate, and
Roberts would be the "swing" vote.
This is bad news, but at the same time, it's why 2018 is so important. This will have huge implications for the census in 2020, so state legislatures/governors' mansions are hugely important, never mind Congress. I've voted in the tiniest of elections since 2017 started and will make it a point to continue to do so when the stakes are so high.
This is the biggest mistake one can make about 2016.
Trump was not a bad candidate. Thinking Hillary was the only problem just sets this up to happen again.
A quibble: I'd say he really was a bad candidate (the only one who wasn't easily above Hillary during the primaries while people like Rubio and Kasich were) and torpedoed himself so many times (going after the Khan family after the convention, going after the Mexican judge, Curiel, his terrible debate preparation), but his strategy was completely underrated. He blatantly showed his hand with going after the rust belt and did it, which had tentacles in other states like Florida, whose southwestern counties are more mid-western than other parts of the state.
So I still agree with you. While a better candidate than Trump, the same was said about Bush, even in 04 (how did the Democrats pick someone who could have lost to Bush?), without people realizing his strategy he was employing and that it was effective. If people think simply nominating someone more progressive will win things in 2020, it won't (though I'd like someone more progressive).