Presidential contender Elizabeth Warren on Saturday unveiled her plan to combat gun violence, including proposals to triple the tax applied to firearm sales and raise the tax on ammunition even more dramatically.

The plan, announced in a post on the blogging platform Medium, comes in the wake of back-to-back mass shootings in El Paso, Texas, and Dayton, Ohio, that left at least 31 people dead.

"In 2017, almost 40,000 people died from guns in the United States. My goal as President, and our goal as a society, will be to reduce that number by 80%," the Massachusetts senator wrote in the plan. "We might not know how to get all the way there yet. But we'll start by implementing solutions that we believe will work."

Warren, who is in the top tier of Democratic presidential candidates, wrote in the plan that she intends to do the following using executive action:

Require background checks for gun purchasers who buy at gun shows or online

Apply the 18-and-up age restriction on gun purchases to more sales

Close the so-called "boyfriend loophole" – current law bars abusive spouses from obtaining weapons, but does not apply to all abusive dating partners

Direct the attorney general to prosecute unlawful gun trafficking and investigate the National Rifle Association for alleged corruption

Direct the bureau of Alcohol, Tobacco, Firearms and Explosives to revoke the licenses of gun dealers that are found to routinely violate the rules

She wrote she would push for the following legislative steps:

Create a federal licensing system for the purchase of any type of gun or ammunition

Boost the excise tax on handguns to 30% from 10% and on ammunition to 50% from 11%

Establish a one-week waiting period for all gun purchases

Increase the minimum age to 21 for all gun sales

Prohibit anyone convicted of a hate crime from owning a gun

The plan is similar in some aspects to the sweeping proposal unveiled by Democratic rival Sen. Cory Booker in May.

Booker proposed a federal gun licensing program, an end to the "boyfriend loophole," and called for an IRS investigation into the NRA to determine whether the group should retain its tax exempt status.

Other candidates have also escalated calls for new gun control measures in response to last weekend's killings.

Former Vice President Joe Biden, the Democratic front runner, said during a CNN interview Monday that he supported universal background checks and a new assault weapons ban. He said he would also put in place a national buyback program.

But Biden was skeptical of proposals that relied on executive action.

"You can, we did that in our administration, act by executive order, on 30 different executive orders," Biden said. "The problem with that is just an executive order, what happens is the next guy comes along and he wipes it all out, which the president did."

Sen. Bernie Sanders of Vermont has proposed expanding background checks and banning the sale of assault weapons. On Friday, Sanders called on the retail giant Walmart to stop selling guns. Warren, Booker, and former Housing Secretary Julian Castro have also called on the retailer to end firearm sales.

In addition to new regulations, Warren also proposed new research in her plan. As president, her budget would include an annual investment of $100 million for the Departments of Justice and Health and Human Services to research the "root causes of gun violence and the most effective ways to prevent it," she wrote.

"Not only have we not passed meaningful legislation in almost a generation, but thanks to the NRA, for decades Congress prohibited federal funding from being used to promote gun safety at all, effectively freezing nearly all research on ways to reduce gun violence," Warren wrote. "Last year, Congress finally clarified that the [Centers for Disease Control and Prevention] could in fact conduct gun violence research — but provided no funding to do so."

While gun control legislation has largely gone nowhere in Congress in recent years, President Donald Trump has suggested he may seek to push forward on new background check rules.

Trump said Friday that he was in talks with congressional leaders about "meaningful Background Checks."

But Trump also said that he was in talks with the NRA, which opposes expanding the existing federal background check system, "so that their very strong views can be fully represented."