Like the lodged container ship in the Suez Canal , the Senate filibuster is set to block much of Democrats agenda in the coming months including on infrastructure, climate change, voting rights, gun control and immigration.

The coming battles over some of the most contentious issues in the country will test senators and their commitment to preserving the way the chamber has run for decades namely keeping the filibuster, which effectively requires legislation to have 60 votes to pass.

Democrats are already warning Republicans that mindless obstruction will amp up pressure to nuke the filibuster and allow legislation to pass with a simple majority. But to do so, the party will first need to convince Sen. Joe Manchin (D-W.Va.) and Kyrsten Sinema (D-Ariz.), two key moderate holdouts.

If they choose to obstruct rather than work with us ... we will push forward and make progress nonetheless, Senate Majority Leader Chuck Schumer (D-N.Y.) said of the GOP at a press conference on Thursday.

On the top of Democrats agenda after the Senate returns from a two-week recess on April 12 is legislation introduced by Sen. Mazie Hirono (D-Hawaii) to give the Department of Justice and local law enforcement more tools to combat hate crimes. The measure is meant to address the wave of attacks against Asian Americans in the country.

The chamber will then move quickly to floor votes on legislation already passed by the Democrat-controlled House of Representatives to expand background checks on gun sales. The bill gained new urgency among Democrats after a pair of gruesome mass shootings in Georgia and Colorado earlier this month.

A landmark voting and ethics reform proposal, called the For the People Act, will also receive a floor vote, Schumer vowed on Thursday. The bill is a top legislative priority of congressional Democrats, who tout it as the most sweeping expansion of voting rights since the Voting Rights Act of 1965.

Democrats are also planning to move on President Joe Biden s proposed $3 trillion infrastructure and jobs package in the coming months, as well as a bill to boost manufacturing, meant to counter Chinas growing influence in the world.

And Democrats are eyeing another vote on a House-passed bill that would create a process for undocumented immigrants brought to the U.S. as children otherwise known as DREAMers to earn citizenship. The Senate passed such a bill in 2013 but it was never taken up by the House at the time.

Much of Schumers to-do list will face fierce GOP opposition.

For example, Republicans say states, not the federal government, ought to have control over how elections are run. They take no issue with the hundreds of bills filed in GOP-dominated legislatures across the country that are meant to limit voting access. The Democrats voting legislation, they say, will create chaos and lead to further distrust in the nations elections.

At least one Senate Democrat shares some of their concerns.

There are some legitimate concerns about the implementation of the For the People Act, especially in rural areas. ... With that in mind, there are bipartisan proposals embedded in this bill that can strike the right balance, Manchin said in a statement on Thursday.

The GOP is also broadly averse to deficit spending or any sort of tax hikes, even on wealthier Americans. Their stance raises questions about how Democrats will push through a huge infrastructure spending bill with bipartisan support, because the Biden administration wants to pay for the measure in part by raising taxes on corporations and rich Americans.

On the regulatory front, Democrats are eyeing overturning a pair of regulations issued late in former President Donald Trump s administration. The first is an Equal Employment Opportunity Commission rule governing how employers can resolve workplace bias claims. The second is a rollback of limitations on methane emissions from oil and gas that were previously issued by the Obama administration.

Schumer can repeal both rules with a simple majority under the Congressional Review Act , which gives Congress the power to nullify any major regulations an executive branch agency finalized within the previous 60 days (not counting periods when Congress was out of session for three days or longer). Republicans used the act, known as the CRA, to hack away at a slew of environmental rules implemented during former President Barack Obama s administration.