If President Obama was serious about ending the wasteful pork-barrel ways of Congress, he had a perfect opportunity last week to show it.

Instead he signed the $410 billion budget measure which included about 8,000 earmarks — pet projects that had been tacked on by lawmakers who are looking after the interests of their home states and their own re-elections.

The White House defended Obama’s apparent spinelessness by saying that the bill was a carryover from the previous administration. But that’s a cop out.

It’s Obama, not George W. Bush, who now wields the veto pen. It’s up to Obama, not Bush, to use it when he is sent legislation that he believes is irresponsible or wasteful or unconstitutional.

It’s easy to talk tough about the spending ways of Congress, as Obama did on the campaign trail and now in office. It’s much tougher to actually force Congress to do things differently.

Earmarks persist because they are popular with incumbents of both parties. There may be a few in Congress, such as Arizona Sen. John McCain, who rail about the special-interest spending, but they are in the vast minority. When McCain, who lost the presidential election to Obama, tried to get his fellow senators to strip the earmarks from the budget bill last week, it got defeated by a 2-to-1 margin.

Lawmakers believe one of their main purposes for being in Washington is to channel federal money back home. Mississippi has been a leading practitioner of this process for decades. It is the one area where the state’s politicians, no matter how divided they may be on other issues, come together. Bennie Thompson, the liberal Democratic congressman, is as big a defender of earmarks as is the state’s supposedly conservative Republican senators, Thad Cochran and Roger Wicker. In fact, Cochran and Wicker accounted for some of the highest number of earmarks of any senators.

Obama says his signature on this legislation signals an “end to the old way of doing business.” We’ll believe it when we see it.