Tensions are already emerging between the White House and some Democrats about how much emphasis the president and Vice President Joseph R. Biden Jr. should give their gun control measures and whether a drawn-out debate over the Second Amendment could imperil the rest of the party’s initiatives, particularly on immigration…

Andrew H. Card Jr., the White House chief of staff to Mr. Bush for six years, said the failure to pass immigration legislation stands as a lesson to second-term presidents, including Mr. Obama, that “you can’t get everything that you want — that’s an unfortunate reality.”

The first year of a second term is about accomplishment and legacy, Mr. Card said, and should be planned carefully before the attention starts shifting away from the president.

“It is the agenda year,” Mr. Card said in an interview. “He will command attention, respect — and probably vitriol — for probably the next three years. After that, he’ll have to adjust to the klieg lights starting to shine on somebody else.”