WASHINGTON — Facing the prospect of grinding Republican roadblocks in Congress, Democrats running for president are emphasizing plans to govern with executive action if they win the White House.

On topics ranging from climate change to gun control to immigration, candidates are looking at ways to go around Senate Majority Leader Mitch McConnell, R-Ky.

Democrats know they face a shaky path to a Senate majority in 2020 and their approach reflects concern from voters and activists that a president could end up hobbled without a plan to deal with McConnell, who has promised to be a "grim reaper" for any progressive legislation that passes the Democratic-controlled House.

"If I'm still the majority leader in the Senate, think of me as the grim reaper. None of that stuff is going to pass," McConnell said in April. "I guarantee you that if I'm the last man standing and I'm still the majority leader, it ain't happening. I can promise you."

In most cases, Democratic candidates are seeking to restore Obama-era initiatives that President Donald Trump has reversed and undo new actions he has taken himself.

"I got a plan for our first 100 days," Sen. Amy Klobuchar, D-Minn., said at a candidate forum in South Carolina last month. "Over 100 things you can do without Mitch McConnell, without the Republicans."

Proposals include rejoining the Paris climate accords and instituting more stringent pollution restrictions on power plants and cars. On immigration, candidates have talked about reinstating protections for recipients of the Deferred Action for Childhood Arrivals program that Trump has sought to remove (the Supreme Court is set to consider the case), and ending his travel restrictions on certain countries.

Frank Sharry, executive director of the immigration advocacy group America's Voice, said proposals such as these — while not a replacement for legislation — reflected a broader pessimism about whether anything might pass Congress soon.

"Even if Trump loses and a Democrat is occupying the White House, the idea that Mitch McConnell and his Senate colleagues will pave the way for a bipartisan immigration deal is laughable," Sharry said. "If you're going to be a credible Democratic candidate on immigration, you have to talk about what you'll do through executive action to undo Trump's radicalism and xenophobia."

In some cases, Democratic contenders have pledged to go further than former President Barack Obama. Sen. Kamala Harris, D-Calif., has been among the most forceful in this regard, putting out a plan not only to allow DACA recipients to stay in the country through executive action, but also provide them with a path to citizenship.

She has proposed new restrictions on guns, including new requirements that firearms dealers perform background checks if they make more than five sales in a year.

Harris is marketing her plans as a way to advance top Democratic goals in Congress if lawmakers refuse to act.

"I will give the United States Congress 100 days to pull their act together, bring all these good ideas together, and put a bill on my desk for signature," she said in the first Democratic debate, discussing her gun proposals. "And if they do not, I will take executive action and I will put in place the most comprehensive background check policy we've had."

Sens. Elizabeth Warren, D-Mass., and Cory Booker, D-N.J., have both released far-reaching immigration plans that include pursuing alternatives to detention for migrants applying for asylum and ending contracts with private companies to oversee detention centers.

"I'll work with Congress to pass broad-reaching reform, but I'm also prepared to move forward with executive action if Congress refuses to act," Warren said in a statement last week.

On climate, Warren and Sen. Bernie Sanders, I-Vt., are vowing to block fossil fuel drilling on public land and promote renewable energy sources through executive action, and Warren has also said she'd order the military to prepare for the impact of climate change. On trade, Sanders says he'd issue an executive order to block federal contracts from going to companies that outsource jobs. On campaign finance reform, Montana Gov. Steve Bullock says he'd require federal contractors to disclose political donations.

Candidates have touted their willingness to increase enforcement in certain policy areas using existing agencies and commissions. Warren has promised to appoint like-minded allies on consumer issues to key posts in order to potentially break up big tech companies such as Amazon, Facebook and Google. Former Housing and Urban Development Secretary Julian Castro has said he'll step up investigations into allegations of police abuse.

At the same time, a handful of candidates are running counter to the trend by emphasizing plans to curb the powers of the presidency in certain areas, most notably the use of force.

South Bend, Indiana, Mayor Pete Buttigieg, an Afghanistan War veteran, has called on lawmakers to "repeal and replace" the military authorization passed after 9/11 to make it more difficult for presidents to take action without going through Congress.

Sen. Michael Bennett, D-Colo., has repeatedly raised this concern and in last month's debate, New York City Mayor Bill de Blasio said both parties "have let (presidents) get away with running the military without that congressional approval." Former Texas Rep. Beto O'Rourke has pledged to "only put troops on the ground in places where Congress authorizes it."

With Democrats sounding the alarm about perceived abuses of power under Trump, the party also faces a choice as to whether it should treat some of his moves as a precedent or voluntarily renounce them before taking office.

The most pressing example is Trump's invocation of emergency powers to find funding to build a wall along the border with Mexico. Democrats decried the move at the time, but also faced immediate questions about whether they might take similar action if the courts sided with Trump.

House Speaker Nancy Pelosi, D-Calif., floated a national emergency on guns, for example, while others suggested climate change might be a ripe area for executive action.

"The temptation is definitely there," Ilya Somin, a law professor at George Mason University, said. "As a general rule, anything one administration gets away with, future administrations are often happy to put in the bank and use."

Democratic presidential contenders have mostly tiptoed around the specifics of what they might do if presented with that possibility. Sanders unveiled a nonbinding resolution this week to declare a "climate emergency" but that included language clarifying that the measure would not grant the government "any special or extraordinary power."

But the Trump administration, like many before it, has illustrated how activist demands to test legal boundaries can take hold once parties switch power.

While he was still serving in the House, Mick Mulvaney, who is now acting White House chief of staff, boasted in 2016 that Republicans would prove that their opposition to Obama's executive orders was "a principled objection" by confronting Trump just as fiercely on similar issues. But when Trump announced a national emergency on the border, which some top Republicans warned would set a dangerous precedent, Mulvaney defended the move by arguing Democrats would do the same thing if they could.

Presidents nonetheless face constraints. The courts are a major barrier, limiting governance by presidential directives alone. While the law grants presidents broad discretion in some policy areas, including immigration and foreign policy, they're more restricted in others, such as taxes and spending.

Trump has run into legal trouble ending Obama's DACA program and most recently his own administration's efforts to put a citizenship question on the census were stymied by the Supreme Court. Obama's power plant regulations were blocked in the courts, as was his effort to expand DACA to millions more undocumented immigrants.

For that reason, some progressives are reluctant to put too much stock in executive action, seeing Congress — however difficult — as their primary focus.

"They're a useful and important tool, but they can't be the whole plan," Democratic strategist Adam Jentleson said. "If you want to make big change, you have to pass legislation."