He isn't a king and that is not his responsibility in the American government. Creating and passing law is the job of Congress. The president only has the last say on whether it goes.

Democrats are not "in power." It's been a split government since the second Obama term. Democrats do not have a majority in both houses of Congress.

Even when the democrats do control both houses, as with the first Obama administration, they do not force the issues. They operate on a "we don't stoop to that level" policy which is why liberal voter get upset with them.

https://www.nbcnews.com/politics/congress/senate-rejects-democratic-bill-codify-abortion-rights-rcna17968

Feb. 28, 2022, 5:32 PM CST By Sahil Kapur and Ali Vitali

WASHINGTON — The Senate voted 46-48 Monday to block a bill pushed by Democrats to codify abortion rights into federal law ahead of an expected Supreme Court decision that could limit access to the procedure.

The legislation, the Women’s Health Protection Act, failed to garner the needed 60 votes to overcome a filibuster and would have fallen short of the 50 votes needed for passage after Sen. Joe Manchin, D-W.Va., joined Republicans in opposition.

The president doesn't make or enact the laws. The president is not the big daddy (or mommy) CEO of America. As long as Rekucklicans are willing to get up and do a long talk -- spoilers, they always will be -- they can essentially force a bill into a 60 vote major to pass instead of a simple 50 (plus the VP) majority to pass.

Doesn't help that there's a senator whose dick is caught in mouse trap baited with a lump of coal.

Don't take this the wrong way. Whenever I see this question I assume the asker is ignorant or willfully obscuring the facts with a leading question.

This would require a new law to be passed and the Democrats do not control the House of Representatives. Even if Harris wins, they also have to win the House and Senat to actually make it legal. That btw is why Biden has not passed much good legislation in the past nearly two years.

All the people pointing out that Biden doesn't have the power to pass laws, only support or veto, are correct. One other aspect is that Biden is sort of a grudging supporter of abortion rights due to his traditional Catholic upbringing. One imagines Harris would be a more enthusiastic advocate