Clement is just doing what he already did in North Rhine-Westphalia: testing how much strain he can put on the administration, checking whether he can push through without compromise. Without regard for the consequences. He already tried this in North Rhine-Westphalia but ultimately failed against Bärbel Höhn. Though "failed" is relative—he got through much more than the Greens liked. This whole game will probably be easier against Trittin. Or even harder—Trittin seems to have genuine staying power (or he's just too dull to notice what he has to take). What's it all supposed to accomplish? No idea, they're politicians, you probably only understand them if you're a trained psychologist.
At tagesschau im Internet you can find the original article.