The answer is that it can have an enormous impact if Republicans play their cards right.
The key is how they handle the federal budget, legislation that requires only a simple majority under the Byrd Rule and for which the president does not have a line-item veto power.
Congress can go line by line through the budget, legislating as it goes, rolling back one after another of Obama's initiatives.
Obviously, the GOP must not overplay its hand. If it uses its power to defund ObamaCare entirely, for example, the president will predictably veto the entire budget and the stage will be set for a replay of the October 2013 shutdown of the government, with the same disastrous consequences for the GOP.
But if Republicans limit their ambitions and carefully choose their targets, they can use line-item changes to control and derail important aspects of Obama's agenda.
The key is to pick targets where public opinion is on the Republican side and not to use the budgetary power in ways that exceed public expectations. Even though a majority of Americans oppose ObamaCare, it would be an overreach to repeal it by defunding it. The process of defunding has no roots in American political memory and is susceptible to Obama's argument that the Congress must pay the bills it has incurred. And, in a fight of that magnitude, as Clinton and Obama well know, the presidential megaphone drowns out all else.
But if Republicans are more limited in their objectives, they can succeed. They could, for example:
- Use the Immigration and Customs Enforcement appropriation to overturn Obama's executive order, expected right after Election Day, to end deportations;
- Use the Health and Human Services line to defund the Independent Payment Advisory Board, dubbed the "death panel" by Sarah Palin;
- Repeal the medical device tax;
- Require release of IRS emails by appending a requirement to the budget for that wayward agency;
- Stop the Federal Election Commission from regulating Internet blogs;
- Block the Federal Communications Commission from its attempts at Internet regulation.
In these and a host of other areas, Republicans can use the budget to thwart and roll back Obama's initiatives.
None of them likely rises to the level where the president would veto the entire budget. And, were he to do so, he would have to fight on ground overwhelmingly favorable to the GOP. He would fail.
And then there is ObamaCare. With the lawsuits invalidating subsidies that go to people who did not pass through the federal exchanges likely to reach the Supreme Court, the chance for a verdict overturning this key element of the healthcare law cannot be discounted.
Both Justices John Roberts and Anthony Kennedy have repeated attacked legislating from the bench, and the lawsuit asks not that they overturn ObamaCare, just that they read the Affordable Care Act and enforce it literally as it is written. If ObamaCare subsidies are overturned, Republicans can replace them with a new system of tax credits without coercion by a simple majority in the Senate (as ObamaCare itself was passed with a simple majority).
Would Obama veto a bill that restores coverage to the 10 million or so people who will have lost their insurance in the court decision?