WASHINGTON — President Obama, whose approval ratings have reached their lowest point, has a new tool in fighting off his lame-duck status: a path to wielding greater executive power over his administration’s priorities and leaving a stronger ideological imprint in the courts.
But the historic changes to Senate rules made last week that hinder Republicans’ ability to block most of the president’s top nominees carry great risk. And they unleash a flood of unanswered questions as Republican lawmakers spend the Senate’s two-week recess considering possible retaliation for what they say is a raw power grab.
Many observers say the provocation in the Senate ensures that Obama’s legislative agenda faces even more gridlock, and is all but dead until after the 2014 elections.
They also say Obama and future presidents will face increasing pressure from their party’s base supporters, who will demand more aggressive choices for courts and Cabinet positions.
“It certainly poisons the atmosphere, which is not conducive to doing the work of the American people,” said Senator Susan Collins, a Maine Republican.
The Senate rule change enacted on Thursday allows approval of most presidential nominees — with the exception of Supreme Court justices — by a simple majority, without the requirement to round up 60 votes to end a filibuster. But the rule changes do not affect legislation, making Republican cooperation a necessity for Democrats to move bills.
That new power, combined with deteriorating relationships with Republican lawmakers, will probably push Obama to assert more executive power.
Obama will have more control not only over his Cabinet and other administrative nominees, but also over a federal appeals court in Washington that has jurisdiction over administrative actions affecting the environment, drug regulations, and other executive-branch actions.
The environment may be a top focus, with Republicans having already said they are unlikely to cooperate on initiatives to curb climate change. Many of the White House’s changes on that front have already been the subject of court challenges.
For example, last year, the DC appeals court struck down an Environmental Protection Agency rule that sets emissions limits for coal-fired power plants that move across state lines.
Similar rules might face a different fate in a more friendly appeals court.
“What this action has done is make it easier for Obama to achieve some of his objectives in his second term,” said Norman Ornstein, a congressional scholar and resident fellow at the American Enterprise Institute, a Washington think tank.
He countered claims that it could worsen the partisan divide.
“The idea that this means gridlock will now ensue — haven’t people seen where we’ve been?” said Ornstein, who co-wrote a book about Washington gridlock.
A key portion of the health care law — setting up an Independent Payment Advisory Board that would make recommendations to rein in the costs of Medicare — can now move forward despite previous Republican opposition to filling the board, Ornstein said. Sarah Palin had derided that board as a “death panel,” making it a top target among conservatives.
Palin, appearing on “Fox News Sunday,’’ derided the filibuster rule change as a “distraction” that was symbolic of “Democrat hypocrisy” because of lawmakers who had opposed the so-called “nuclear option” not long ago now think “it’s the greatest thing since sliced bread.”
“This new rule change, it stinks,” Palin said.
Without the filibuster, Obama may also fill several lower-level positions in key regulatory agencies, some of which have been vacant for months or even years. Environmentalists are eager for key appointments such as the head of the Office of Water at the Environmental Protection Agency and several positions in the Department of Interior. The long wait for confirmation has led some nominees to withdraw.
As he fills those picks and selects new judges, Obama will be under pressure from activists in his own party to make more aggressively ideological picks.
He used the threat of Republican opposition, for example, when he passed over Elizabeth Warren to lead the Consumer Financial Protection Bureau, which devastated liberals and helped propel her US Senate career.
Republicans said that in the long term, the rule changes will empower the extremes of both parties. Senator Jeff Flake, an Arizona Republican, said he worries about that prospect, even if the rule changes eventually benefit his own party.
“I fear that once Republicans get the majority, it’s very tough to tell your base that you’re going to diminish your own authority,” he said.
Obama will not have an entirely free hand in loading the courts. There are 93 court vacancies that Obama can fill: 75 in the district courts and 18 in the court of appeals. Republican senators still have some tools at their disposal to make appointments difficult, such as invoking the blue-slip tradition requiring both home state senators to support a nomination before it is processed.
James P. Manley, a Democratic strategist and former aide to the Senate majority leader, Harry Reid, said Republicans still have many options to “gum up the Senate.”
“It’s difficult to imagine the Senate becoming even more dysfunctional than it is now. But the fact of the matter is, depending on how Republicans want to play it, it can be,” Manley said.
The institution’s rule book is replete of arcane customs that can be exploited to slow the pace of business. For example, it requires unanimous consent every day to hold committee hearings. If one senator objects, every panel in the building is halted and no others can begin for an entire day.
And before adjourning for recess last week, Reid failed to nominate a batch of district court judges, which is routinely done before a long break. That too requires unanimous consent and Democrats, aware of Republicans’ raw nerves, were reluctant to provide a platform for dissent.
Upon return from a two-week recess in December, the Senate will focus on more modest goals, including a deal to prevent another government shutdown that is not expected to include any broader proposals to change the tax structure or reduce entitlement spending. Senators will also try to pass an annual defense bill that stalled Thursday afternoon.
The Obama administration is also renewing an effort to win approval for an international treaty designed to protect disabled people. The treaty failed last December, falling five votes shy of the two-thirds majority required. Senator John McCain, who supports the treaty, said the rule changes could hurt the effort to win more supporters.
“That will put a chill through all of that,” McCain said.
The historic rule change could also haunt Obama’s long-term legacy, warned Julian Zelizer, a Princeton history professor. If the GOP wins big in 2014 and 2016, he said, “this could pave the way for Republicans to have a lot more leeway to undercut a lot of what Obama did.”
“That’s a risk Democrats just took,” Zelizer said.Noah Bierman can be reached at email@example.com. Tracy Jan can be reached at firstname.lastname@example.org.