There are two ways of looking at President Obama's executive action on immigration: as a Constitutional matter, and as a political matter.
As a Constitutional matter, it is a very troubling expansion of executive power, and almost certainly a violation of the Constitution. However, it is not as black-and-white as either the President and his allies on the left or the president's opponents on the right would like you to believe. The Congress, not the President, is the only branch of government that can legislate — and amending existing legislation such as our body of immigration laws is an exercise of the legislative function every bit as much as is the creation of new legislation. Senators Cruz and Sessions are two of the most vocal, credible and effective spokespeople for this point of view. Senator Cruz said, "This is a wholesale refusal by President Barack Obama to follow our immigration laws." Senator Cruz and other like-minded Constitutionalists see it as a simple matter of President Obama legislating without the power to legislate.
On the other hand, the President and his almost comically sycophantic Justice Department put together a 33 page internal memorandum that the Administration will not release to the public saying that the President was on solid ground, because he would merely be exercising prosecutorial discretion. That is, because it is logistically impossible to prosecute every single person who may have broken our immigration laws, the President can set forth a standard of which ones he'd prosecute and which ones he wouldn't. That's not unlike a District Attorney who elects to prosecute only those demonstrators in a civil disturbance or riot who actually assaulted someone, rather than everyone involved in the demonstration that arguably disturbed the peace. At what point does exercising so much prosecutorial discretion cross the line and become an intentional and unconstitutional act of failing to faithfully execute the laws?
The Presidential oath of office doesn't actually say that he swears to faithfully execute the laws of the United States, by the way. The Presidential Oath of Office is in Article Two Section I — and it merely says that the President swears to faithfully execute the office of President of the United States. Several paragraphs later, in Article Two Section III, there is a clause known as the Faithful Execution Clause. It says that the President must "take care that the laws be faithfully executed." In an article explaining the history of how that clause has been observed, Wikipedia notes that President George Washington observed, "it is my duty to see the Laws executed: to permit them to be trampled upon with impunity would be repugnant to" that duty. It's my belief that President Obama's executive action goes far enough beyond the limits that other Presidents have observed regarding their prosecutorial discretion as to meet Washington's standard of repugnance to the sworn duty of the President. In other words, those who argue that the executive action exceeds the President's constitutional limits are on much sounder ground than those who argue that it's really no different than executive actions taken by other Presidents. To put it in the simplistic language of a sports contest, the President loses this argument.
That brings up the second way of looking at this issue — as a political one, which it surely is. And that's where I think the President wins. Even though Republicans, conservatives and Constitutionalists may all be agreed that President's action violates the Constitution, what should they do about it? House Speaker John Boehner's lawsuit may well be the best that they can do — take the President to court, hope that it gets all the way to the Supreme Court quickly, and then take whatever pleasure they can extract from a ruling from the court that amounts to little more than a slap on the hand of the President. Every other action, such as withholding funds, shutting down the government or impeaching the President, is almost certain to cause a bigger negative political backlash than any actual negative impact on the President. And, any of those actions will take a long time to play out — all during which time the President and his allies will engage in the most divisive kind of racist demagoguery designed to persuade all minorities and recent immigrants, legal or illegal, that the Republicans hate them and that the Republican Party is really just the white party.
If the Republicans pursue any of the more aggressive means of opposing the President's unlawful expansion of executive power, their victory will precisely fit the definition of a Pyrrhic victory. That's a victory that comes at such a devastating cost that it's tantamount to a defeat. The Greek general Pyrrhus is said to have remarked to a fellow officer after one winning battle in which thousands of his soldiers died that if he achieved one more such victory, he would be utterly ruined. Can Republicans learn from Pyrrhus — whose victory nearly 2,300 years ago was so costly?