“How’re you doing,” a character asks in “Spring,” Ali Smith’s new novel, “apart from the end of liberal capitalist democracy?”

“Spring” is the third novel in a projected seasonal cycle that began with “Autumn” in 2017 and continued last year with “Winter.” This is the most political book thus far in this earthy and humane series. Its heart is worn far out on its sleeve. It beats arrhythmically somewhere down near the knuckles.

Smith is not going to ride out this tumultuous political moment artistically, as if she were a car parked under an overpass during a storm. She’s delivered a bracing if uneven novel, one that, like jazz, feels improvised. “Spring” is tendentious at times, but it taps deeply into our contemporary unease. It’s always alive.

Some of the things this novel comes out against: Brexit, 24-hour news channels, immigrant detention centers, shrinking library hours, global warming, CCTV cameras, bad manners, giving away your DNA, emojis, private security firms and, not least of all, the American president.