The plan, passed Monday by the state House, would take effect only if states representing a majority of the nation’s 538 electoral votes adopted the same change.
Fat chance that will happen soon.
Such language makes such legislation even more ridiculous than it would be otherwise. Suppose states representing 260 votes were to pass legislation that unconditionally gave their votes to the popular-vote winner; Maryland and another 10-EV state have passed its conditional version. Then a Republican wins the popular vote and the presidency hangs on the two states' EVs.
If either state were to balk at awarding their EVs to the popular-vote winner, that would give the other state legitimate reason to refuse to cast its vote likewise. Once the second state refused, there would no longer be a majority of EVs cast according to popular vote, so the former state would cease to be under any obligation to cast its own votes that way.
The only real effect of Maryland's scheme would be to guarantee that neither party could be seen as having won legitimately.