While that natural language determiners denote conservative functions (Keenan & Stavi 1986) is perhaps the most commented on semantic universal, it arguably remains unexplained. I will revisit a promising approach based on the idea that copy theory of movement (Chomsky 1995) makes non-conservative determiners semantically vacuous (Chierchia 1995, Fox 2002, 2003, Sportiche 2005). The only serious study of this idea was done by Romoli (2015) with the surprising conclusion that non-conservative determiners may very exist but we cannot be sure as, within copy theory, such determiners are bound to yield the same truth-conditions as conservative ones. I will address Romoli’s skepticism by leveraging presupposition projection and Late Merge (Lebeaux 1988 and subsequent work) to argue that all determiners are in fact lexically conservative. I will then argue that, with an auxiliary assumption about the denotation of determiners, an implementation of Schlenker’s (2009) theory of projection coupled with Fox’s (2002, 2003) rule of trace conversion correctly predicts all determiners to be conservative. Finally, I will stress-test the proposal by considering local accommodation, domain restriction, wholesale late merger (Bhatt & Pancheva 2004, Takahashi & Hulsey 2009), and certain non-conservative uses of “only” (von Fintel & Keenan 2018, Zuber & Keenan 2019).