These orders are in addition to laws that Obama wants Congress to pass. Here, according to the White House, are what the 23 executive actions will do, without congressional approval:
1. "Issue a presidential memorandum to require federal agencies to make relevant data available to the federal background check system."
2. "Address unnecessary legal barriers, particularly relating to the Health Insurance Portability and Accountability Act, that may prevent states from making information available to the background check system."
3. "Improve incentives for states to share information with the background check system."
4. "Direct the attorney general to review categories of individuals prohibited from having a gun to make sure dangerous people are not slipping through the cracks."
5. "Propose rulemaking to give law enforcement the ability to run a full background check on an individual before returning a seized gun."
6. "Publish a letter from ATF to federally licensed gun dealers providing guidance on how to run background checks for private sellers.
7. "Launch a national safe and responsible gun ownership campaign."
8. "Review safety standards for gun locks and gun safes (Consumer Product Safety Commission)."
9. "Issue a presidential Memorandum to require federal law enforcement to trace guns recovered in criminal investigations."
10. "Release a DOJ report analyzing information on lost and stolen guns and make it widely available to law enforcement."
11. "Nominate an ATF director."
12. "Provide law enforcement, first responders, and school officials with proper training for active shooter situations."
13. "Maximize enforcement efforts to prevent gun violence and prosecute gun crime."
14. "Issue a presidential memorandum directing the Centers for Disease Control to research the causes and prevention of gun violence."
15. "Direct the attorney general to issue a report on the availability and most effective use of new gun safety technologies and challenge the private sector to develop innovative technologies."
16. "Clarify that the Affordable Care Act does not prohibit doctors asking their patients about guns in their homes."
17. "Release a letter to health care providers clarifying that no federal law prohibits them from reporting threats of violence to law enforcement authorities."
18. "Provide incentives for schools to hire school resource officers."
19. "Develop model emergency response plans for schools, houses of worship and institutions of higher education."
20. "Release a letter to state health officials clarifying the scope of mental health services that Medicaid plans must cover."
21. "Finalize regulations clarifying essential health benefits and parity requirements within ACA exchanges."
22. "Commit to finalizing mental health parity regulations."
23. "Launch a national dialogue led by Secretaries Sebelius and Duncan on mental health."
[Updated at 12:43 p.m. ET] Senate Democratic leadership sources tell CNN that passing any new legislation will be extremely difficult because more than a dozen vulnerable Democrats from conservative states will probably resist much of what the president is pushing, according to CNN's Dana Bash.
These Democratic sources say the most likely legislation to pass will be strengthening background checks, since it is the least overt form of gun control and it also appeals to gun rights advocates' emphasis on keeping guns away from people with mental health and criminal problems.
[Updated at 12:42 p.m. ET] Reaction to Obama's announcement is starting to come in. From Connecticut Gov. Dannel Malloy, whose state was the site of the December 14 school massacre that prompted Obama to examine gun control steps:
"In the hours after the worst of our fears were confirmed, in the midst of the grief and sorrow over the loss of 20 innocent children and six dedicated educators at Sandy Hook Elementary School, there was one question on the minds of people across Connecticut and around the nation: How do we make sure this never happens again? Today the president took the critical first step toward answering that question. The common sense measures he proposed today are something that we should all be able to agree on, and I want to commend him and the vice president for their work on this issue."
From Michael Steel, spokesman for House Speaker John Boehner:
"House committees of jurisdiction will review these recommendations. And if the Senate passes a bill, we will also take a look at that."