ANALYSIS — House Republicans remain divided on how to handle former President Donald Trump, as their 35 defections on Democrats’ proposal for a commission to investigate the Jan. 6 riot at the Capitol showed. But more consequential cracks in party unity, at least so far as the legislative agenda goes, are appearing among Democrats.

Those disagreements — about taxes, voting rights and U.S. policy toward Israel — could play a role in how much of President Joe Biden’s expansive agenda Democrats can enact this year, given that near-total unity will be necessary.

“I am strongly for the SALT repeal, the cap removed, and will do everything I can to get it done,” Senate Majority Leader Charles E. Schumer said of the $10,000 limit on federal deductions for state and local taxes that Republicans established in their 2017 tax law. Sen. Bob Menendez echoed Schumer’s point, saying that “fairness and equity demands” the cap’s repeal.

The cap falls hard on Schumer’s high-income constituents in New York, and Menendez’s in New Jersey. But their opposition to it conflicts with their criticism of the 2017 law as a giveaway to the rich, since it lowered income, capital gains and corporate tax rates.

Their position also divides Democrats. Schumer and Menendez’s fellow senator, Vermont independent Bernie Sanders, told Axios that the SALT cap should remain: “You can’t be on the side of the wealthy and powerful if you are going to really fight for working families.”

Biden’s plan to raise taxes on the well-to-do in other areas, such as by eliminating the stepped-up basis that allows homeowners to pass on their properties at death to their heirs without incurring capital gains tax, will hit many of the same people angry about the SALT cap.

And the disquiet among Democrats on SALT could spill over. Homes in affluent Democratic cities have risen in value more than those in most Republican-controlled areas and in many neighborhoods, average prices are now more than $1 million. So despite an exemption for gains up to that amount, heirs in states like New York, New Jersey, California and Massachusetts will have to pay capital gains on inherited homes more than those in places like Texas or Idaho — perhaps at Biden’s proposed 39.6 percent rate — and the number of those paying the tax will only grow as home prices do.

A progressive push

The Democratic left also demonstrated its unwillingness to give ground to the party’s establishment wing after Hamas, the Iranian-backed group that holds power in the Gaza Strip, began launching rocket attacks on Israel on May 10 and Israel responded with air strikes.

Michigan Democrat Rashida Tlaib, who is Palestinian American, called out the party’s pro-Israel wing May 13 on the House floor, saying, “Palestinians aren’t going anywhere no matter how much money you send to Israel’s apartheid government.”

But a push from Tlaib and her allies to halt the sale of $735 million in military equipment to Israel ran into opposition from Biden and Democratic leaders. House Majority Leader Steny H. Hoyer expressed the view that was once near-universal in Congress that Hamas is “a terrorist organization who has made it very clear that they want to see Israel obliterated.” Hoyer said Israelis had a “right to defend themselves.”

In 2002, pro-Israel donors and Democratic Party leaders helped oust two House Democrats who’d sided with the Palestinians and spoken out against Israel, Cynthia A. McKinney of Georgia and Earl F. Hilliard of Alabama. Both lost primaries that year, and Democratic unity on Israel policy was restored.

But since, sympathy in the party for the Palestinians has grown and become associated among progressives with the Black Lives Matter movement. The disagreement isn’t going away — Sanders plans to force a vote in the Senate on the military equipment sale — and Democrats will have to hope their differences on the issue don’t make it more difficult to cooperate on domestic matters.

There are hints that the absolutism of some on the party’s left is frustrating party leaders. With Congress sure now to miss the goal many lawmakers shared with Biden to pass a policing bill by the anniversary of the death of George Floyd last May 25 in Minneapolis, there were indications that some Democrats are more willing to compromise on the critical issue of qualified immunity than others.

Congressional Progressive Caucus Chair Pramila Jayapal and several like-minded representatives wrote to party leaders on May 20 to insist that any policing bill remove police officers’ immunity from civil suits.

But House Majority Whip James E. Clyburn told CNN earlier this month he was willing to change a provision in the Democrats’ bill that would allow victims of police misconduct to sue individual officers for civil damages. Republicans say that language would make it more difficult for police to act in perilous situations.

“Sometimes you have to compromise,” Clyburn said. He added that he was not one to “sacrifice good on the altar of perfect.”

The lead Republican negotiator on the bill, South Carolina Sen. Tim Scott , has proposed making it easier to seek civil damages from police departments. But it’s not clear how that would deter misconduct, since cities already pay millions of dollars each year in settlements.

Manchin in the middle

There was also another indication that the leading Democratic moderate in the Senate, Joe Manchin III of West Virginia, isn’t going to make it easy for Schumer to move forward with the party’s expansive voting rights, campaign finance and ethics bill, despite Schumer’s insistence that it’s a “must do.”

Manchin has previously said he believes any such far-reaching change to state election rules must be bipartisan. To that end, on May 17, he and Alaska GOP Sen. Lisa Murkowski wrote to Schumer, Speaker Nancy Pelosi, Senate Minority Leader Mitch McConnell and House Minority Leader Kevin McCarthy to urge action on legislation to reinstate civil rights rules requiring states and localities to seek Justice Department approval before making changes to their voting laws. Those rules, which date to the 1965 Voting Rights Act, were dismantled by a 2013 Supreme Court decision.

As Murkowski’s signature shows, there’s some bipartisan support for restoring the rules, which targeted jurisdictions with a history of bias against African Americans. But action on that could reduce momentum for the Democrats’ broader bill, which Democratic leaders have framed as an answer to a spate of new voting rules in Republican-controlled states that they say are racist.

Manchin would have to support a change in the filibuster for Democrats to pass that bill, which Republicans uniformly oppose, but Schumer dismissed the Manchin overture. “The Voting Rights Act is actually authorized through 2032,” Schumer said. “So, their letter to us saying, ‘Authorize it,’ well, it’s pretty much done.”

Democrats spent much of last week castigating Republican leaders for refusing to support a Jan. 6 commission, even after Democrats had agreed to give the GOP equal seats on the panel and a veto on subpoenas. Republicans acknowledged that they feared Democrats would use the panel to hurt them in the run-up to the 2022 elections.

Schumer promised a Senate vote to put them on record. On that, he can expect his caucus to vote in unison. But the weeks ahead will reveal more about whether Democrats are unified enough to pass their more far-reaching bills, led by the voting rights measure and Biden’s proposals to spend another $4 trillion to stimulate the economy, rebuild infrastructure, promote green energy and help working families with their expenses.