Nope. If you can get an erection in the morning, the vasodilatation mechanism works, so Cialis/Viagra won't help. If the mechanism works, but you still cannot get an erection when you're with your partner, the problem could be psychological, say you're not attracted anymore to your partner, anxiety, stress, all stopping you from getting aroused. And you need those neurons or endotheliums to fire. Another example is drugs that are vasoconstricting, stimulants like amphetamines or cocaine, which even though create a high arousal state, they are so vasocontricting that it's hard to achieve an erection (so Cialis/Viagra helps, but it's not indicated to combine drugs that combat eachother).