Roberts spent much of the past year as a leader in limbo: The Senate’s refusal to consider President Obama’s nominee to replace the late Antonin ­Scalia left the Supreme Court with a 4-to-4 ideological deadlock in several cases. But Roberts earned plaudits for keeping things humming relatively smoothly. And court watchers say it’s telling that President Trump’s first high-court nominee, Neil Gorsuch, is very much in the Roberts mold: a conservative with the intellectual and diplomatic skill to forge centrist consensus as needed.