Star Wars/ SDI is not functional/operational or ready. It was defunded while being researched when the USSR fell.
No funds went to produce them.
Some systems could stop a handful of warheads. But not enough to matter.
Some warheads or missiles with multiple warheads would fail, but again not enough to matter.
Every target, on both sides is targeted with multiple warheads.
Targets--
--Every military base (bombers, fighters, tanks, infantry, subs, surface ships)
--Every powerplant
--Every rail center
--Every research center
--Every communications hub
--Every command/control center
--Every large population center
--Every airport with longer than x thousand feet runway
--Every port
--Every large bridge
--Every dam
--Every missile silo
Each targeted with 3 to 10 warheads of 500 kt to 1.5 mt

Even if 50% failed to reach the targets, it is still massive destruction that would destroy the viability of the target nation.

So yes, they could hit us.
But we can hit them too. That is why it is not a good idea to poke at them.