The Manchin-Toomey Amendment, which would have expanded national background checks and closed some gun-show loopholes for gun purchases, was defeated in the U.S. Senate yesterday, likely ending President Obama’s push for new gun laws. There are many political lessons to be learned from, and reasons for, the bill’s defeat.

The bill had 54 votes (55 if we include the Majority Leader’s, who voted against it for procedural purposes), four more than necessary for passage, but six short of the 60 needed to head off a filibuster. The Senate’s rules require 60 votes to close off debate and require a vote. Had the Senate Democrats wanted to make a major issue of the bill, they could have forced the matter and allowed the Republican minority to filibuster and then call for a vote–in one day, one week, or one month, who knows–whenever the GOP decided to stop talking. Of course, this is difficult for everyone. It stops the legislative process for other bills, brings significant media attention to the issue, and requires Senators to be within proximity of the floor because a vote could occur in a short period of time.

Obviously, this is all GOVT 101, but if Democrats had wanted to pass the bill, they could have pushed the matter to its final conclusion. The reality, I believe, is that most of them are happy to see this go away. The polls seem to indicate that majorities support expanded background checks and assault weapons bans, but, as Matt Vasilogambros pointed out here, those polls fail to capture intensity. Gun rights advocates are far more committed and active on the issue, so even though they may be a minority, they are a potent political force.

This is especially true in states that tilt Republican at the presidential level. Four Democrats voted against Manchin-Toomey and all of them hail from nationally Red states–Montana, Alaska, North Dakota, and Arkansas. The pressure brought to bear on them may have been intolerable, especially in the short run. Three of the four are up for re-election next year (Begich–AK, Heitkamp–ND, and Pryor–AR).

Finally, this is a severe blow for President Obama. He staked the prestige of his office on gun control. He waived every bloody shirt he could find, resurrected the ghosts of Newtown whenever it suited his fancy, and ceded his most recent national address to a Newtown victim’s mother. He campaigned around the country in front of every camera he could find and he could not persuade a handful of Democrats to stay loyal in the Senate, a chamber his party controls. Whatever political capital he brought into his second term, a large chunk of it just swirled down the drain.

This is fairly typical, I am afraid. Second terms are historically bumpy and can get ugly. Bush suffered the failure of Social Security reform, Clinton was impeached, Reagan struggled under the scandal of Iran Contra and lost Republican control of the Senate in 1986. Do not be surprised if President Obama suffers even more. After all, we are only a few months into this term.

In some ways, this may strengthen the GOP’s hand when it comes to budgetary and entitlement reforms. Obama will, soon, become overly conscious of his historic legacy and it is possible he will be goaded into negotiations as a result. At the same time, President Obama is more ideological and committed than any President since Reagan, if not Lyndon Johnson.