Democrats are projected to win back the House in the November midterm elections, and they are already planning a muscular agenda of setting their own policy priorities for the first time since 2010 and investigating the Trump administration.

Controlling the House doesn't mean Democrats can pass any bill they want into law — a split Senate will continue to act as a hurdle and President Trump still has the power to veto bills he doesn't like.

But Democrats would still be able to set the agenda in the House. Here are seven things they're likely to try:

1. Investigate, investigate, investigate

Democrats have complained from the start that the Trump administration needs to be held more accountable. But without the majority's power to subpoena Trump officials, Democrats have been unable to force a reckoning with the administration.

Special counsel Robert Mueller is already investigating Trump's alleged ties to Russia. But if Democrats control the House, they will likely launch investigations into everything from possible conflicts of interest involving Trump’s son-in-law and senior adviser Jared Kushner to a scandal involving Housing and Urban Development Secretary Ben Carson’s spending habits, including a $31,000 furniture purchase.

[More: It’s not over: Democrats vow to investigate Kavanaugh]

In the past eight years Republicans have controlled the House, Democrats have counted 52 instances where House Oversight Committee Republicans blocked their subpoena motions.

Former spokesman for Republican Rep. Darrell Issa of California told CNBC that Democratic staff on the House Oversight Committee would be doubled and filled with investigators if Democrats took the House.

2. Gun control

Since Trump took office, there have been two major mass shootings carried out in the U.S., which has energized Democrats to call for stricter gun regulations.

House Minority Leader Nancy Pelosi, D-Calif., who wants to be House speaker again, told Politico that one of the first bills to hit the floor under Democratic control would seek to make it more difficult for people to purchase a gun.

The Democratic leader on Wednesday met with survivors of the Parkland, Fla., high school shooting, which claimed 17 lives in February, and said she would keep true to her promise and push for legislation that would keep “guns out of the hands of people who should not have them.”

Despite the high-profile shootings at Parkland and a concert in Las Vegas, Trump and the GOP have been hesitant to push through any major gun legislation, as a large part of their base is for less government involvement in gun sales and regulation.

3. Trump's tax returns

Trump never released his tax returns when he was campaigning, and Democrats can be expected to use a law that will let them look over his tax filings even if Trump resists, Politico reported.

[Larry Kudlow: Trump knows taxes because he’s been 'dodging them for all these years']

The law lets the chairman of the House Ways and Means Committee to look over anyone's tax returns. As a result, obtaining and analyzing Trump’s returns could be one of the first things Democrats do with a House majority.

Trump was the first president in 40 years not to release his tax returns. Democrats are particularly interested in Trump’s documents because they could reveal conflicts of interest posed by his businesses and his position as president.

4. Internet regulation

Trump has kept true to his promise to decrease the amount of regulations stifling industry workers, which he made during his campaign.

But the push for regulations will likely make a comeback under Democrats, particularly in the area of the Internet. Ever since the U.S. intelligence community said Russians were able to influence the 2016 presidential election through social media sites such as Facebook and Twitter, Democrats have been looking for ways to impose and tighten regulation on those sites.

Ideas for regulations run the gamut from requiring sites to label bot accounts to making platforms legally liable for claims like defamation and invasion of privacy, a leaked Democratic document revealed.

5. Taxes

Democrats are using the Republicans' $1.5 trillion tax cut as a campaign strategy, claiming the cuts only benefit corporations and the top 1 percent.

A House victory for Democrats in November’s midterm elections would let them start pushing for a complete tax overhaul, including an increase in corporate tax rates.

Even if these plans can't pass the Senate or be signed by Trump, Democrats can be expected to push for reforms that would raise taxes on high-income earners and set up Democrats to argue that a Democratic president is needed in 2020 to sign these reforms into law.

6. Drug prices

Democrats introduced a bill over the summer that would allow for Medicare to negotiate its prices directly with pharmaceutical companies, a sign of things to come if Democrats control the House.

Trump previously pushed for direct negotiating power, which is usually associated with having Democratic support, but it hasn't been a priority for the GOP.

Democrats would likely make it a priority in an effort to lower drug prices for consumers. Rep. Lloyd Doggett, D-Texas, said that Democrats introduced the bill in July so it could be ready for Democrats to pass if they win back the House.

7. Immigration and border security

Trump has warned that if Democrats take over, they'll look to ease federal immigration laws, and Democrats have admitted they would look to make changes there.

Trump has threatened to end protections for immigrants brought to the country illegally as children, that former President Obama Barack created, and has said Congress should create such a program if it can.

[Trump: Democrats figure caravan migrants will vote for them]

Democrats have said several times they want such a bill, but have complained that House Republicans haven't put one forward. They've also threatened to vote against spending bills under Congress first passes legislation to help the so-called Dreamers.

Controlling the House again would let them take steps in that direction, and could put them in a position to negotiate with Trump over priorities, such as reforms to U.S. policy on how and when immigrant children can be detained.