Gardner didn't even make an effort to get reelected and wouldn't matter if he did. He is beyond toast. Seeing him lose will be immensely satisfying.
This much is true. Gardner
endorsed Trump for reelection a few months ago, and I'm sure you're aware of his recent exchange with reporters over impeachment, in which he dodged their questions and refused to provide definitive answers. Moreover, Gardner voted against overturning Trump's emergency declaration, and hasn't broken with Trump on anything, to say nothing of his vote for Kavanaugh. He's done everything possible to destroy his chances here, slim as they were to start. And I know from personal experience that his constituent service is terrible. I too, will be glad when he is defeated.