President Bush’s suggestion yesterday that he would cancel lawmakers’ pork-barrel projects has prompted a backlash from appropriators on Capitol Hill. Sources tell me that even the Christmas holiday hasn’t tempered the anger of earmark-loving lawmakers who are aggressively lobbying Bush to reconsider.

With opposition mounting to Bush’s idea, fiscal conservatives made sure they didn’t stand by silently. This afternoon a coalition of government watchdogs released a letter asking Bush to issue an executive order directing all federal agencies to ignore non-legislative earmarks. The letter followed a policy paper by my colleague Brian Riedl of the Heritage Foundation outlining three specific steps Bush could take: canceling non-binding earmarks by executive order, refusing to implement earmarks that are not sufficiently specific, and banning “phone-marking.”

The earmark debate has also caught fire on the campaign trail. Mitt Romney today called on Bush to “eliminate as many of these earmarks as possible.” He added:

Change in Washington begins when we change the culture that allows earmarks, pet projects and wasteful spending to thrive in the place of being good fiscal stewards of the taxpayers’ money.

Romney’s statement comes just days after rival Rudy Giuliani released an ad condemning earmarks.

Of course, this issue is nothing new for Sen. John McCain, who has railed against earmarks and pork-barrel projects for years. It’s refreshing to see McCain’s adversaries joining him. Even though McCain missed the vote on the $555-billion omnibus, he made his views crystal clear on the Senate floor earlier in the week:

When we ram through a gigantic bill, spending hundreds of billions of taxpayer’s dollars with little or no debate because we want to go home for Christmas, we send the message to the American people that we are not serious enough about our jobs. … We are sending the signal that it is more important for us to be able to issue press releases, and I am sure hundreds of them will be going out today, about how much pork we have been able to get for our states and districts, than we are about good government and fiscal responsibility. How can we, in good conscience, defend this behavior to the American people?

Bush has the backing the conservative base and now a handful of presidential candidates. But does he have the courage to shut down the favor factory?