Here is another example of how Election is tied to the “P” in TULIP and is essentially understood to be about Eternal Security.
This doctrine [Perseverance] does not stand alone but is a necessary part on the Calvinistic system of theology. The doctrines of Election and Efficacious grace logically imply the certain salvation of those who receive these blessings. If God has chosen men absolutely and unconditionally to eternal life, and if His Spirit effectively applies to them the benefits of redemption, the inescapable conclusion is that these persons shall be saved.
Loraine Boettner, The Reformed Doctrine of Predestination, 8th ed. (Grand Rapids, Eerdmans 1958), p. 182)