The Heritage Foundation is my favorite think tank, and they have a summary of what the law would do:

The Issue

H.R. 0ne would federalize and micromanage the e1ection process administered by the states, imposing unnecessary, unwise, and unconstitutional mandates on the states and reversing the decentralization of the American e1ection process—which is essential to the protection of our liberty and freedom. It would implement nationwide the worst changes in e1ection rules that occurred during the 2020 e1ection and go even further in eroding and eliminating basic security protocols that states have in place. The bill would interfere with the ability of states and their citizens to determine the qualifications and eligibility of v0ters, to ensure the accuracy of v0ter reg1stration rolls, to secure the fairness and integrity of e1ections, to participate and speak freely in the political process, and to determine the district boundary lines for electing their representatives.

What H.R. 0ne Would Do

• Seize the authority of states to regulate v0ter reg1stration and the voting process by forcing states to implement early voting, automatic v0ter reg1stration, same-day reg1stration, online v0ter reg1stration, and no-fault absentee bal1oting.
• Make it easier to commit fr4ud and promote chaos at the pol1s through same-day reg1stration, as e1ection officials would have no time to verify the accuracy of v0ter reg1stration information and the eligibility of an individual to v0te and could not anticipate the number of bal1ots and precinct workers that would be needed at specific pol1ing locations.
• Degrade the accuracy of reg1stration lists by requiring states to automatically register all individuals (as opposed to “citizens”) from state and federal databases, such as state Departments of Motor Vehicles, corrections and welfare offices, and federal agencies such as the Social Security Administration, the Department of Labor, the Federal Bureau of Prisons, and the Center for Medicare and Medicaid Services of the Department of Health and Human Services. This would register large numbers of ineligible v0ters, including aliens, and cause multiple or duplicate reg1strations of the same individuals and put federal agencies in charge of determining a person’s domicile for voting purposes (as well as that individual’s taxing state).
• Constitute a recipe for massive v0ter reg1stration fr4ud by hackers and cyber criminals through online v0ter reg1stration that is not tied to an existing state record, such as a driver’s license. It would make it a criminal offense for a state official to reject a v0ter reg1stration application even when it is rejected “under color of law” because the official believes the individual is ineligible to v0te. It would also require states to allow 16-year-olds and 17-year-olds to register; when combined with a ban on v0ter ID and restrictions on the ability to challenge the eligibility of a v0ter, this would effectively ensure that underage individuals could v0te with impunity.
• Require states to count bal1ots cast by v0ters outside of their assigned precincts, overriding the precinct system used by almost all states that allows e1ection officials to monitor v0tes, staff pol1ing places, provide enough bal1ots, and prevent e1ection fr4ud.
• Mandate no-fault absentee bal1ots, which are the tool of choice for v0te thieves. It would ban witness signature or notarization requirements for absentee bal1ots; force states to accept absentee bal1ots received up to 10 days after Election Day as long as they are postmarked by Election Day; and require states to allow v0te trafficking (v0te harvesting) so that any third parties—including campaign staffers and political consultants—can pick up and deliver absentee bal1ots.
• Prevent e1ection officials from checking the eligibility and qualifications of v0ters and removing ineligible v0ters. This includes restrictions on using the U.S. Postal Service’s national change-of-address system to verify the address of registered v0ters; participating in state programs that compare v0ter reg1stration lists to detect individuals registered in multiple states; or ever removing registrants due to a failure to v0te no matter how much time has elapsed. It also would substantially limit the public release of v0ter reg1stration information, making it almost impossible for nonpartisan organizations to verify the accuracy of reg1stration rolls, and prohibit states from using undeliverable e1ection mail as a basis for challenging a registrant’s eligibility.
• Ban state v0ter ID laws by forcing states to allow individuals to v0te without an ID and merely signing a statement in which they claim they are who they say they are.
• Expand regulation and government censorship of campaigns and political activity and speech, including online and policy-related speech. H.R. 0ne would impose onerous legal and administrative compliance burdens and costs on candidates, citizens, civic groups, unions, corporations, and nonprofit organizations. Many of these provisions violate the First Amendment, protect incumbents, and reduce the accountability of politicians to the public; its onerous disclosure requirements for nonprofit organizations would subject their members and donors to intimidation and harassment—the modern equivalent of the type of disclosure requirements the U.S. Supreme Court in NAACP v. Alabama (1958) held violated associational rights protected by the Fourteenth Amendment.
• Reduce the number of Federal Election Commission members from six to five, allowing the political party with three commission seats to control the commission and engage in partisan enforcement activities.
• Require states to restore the ability of felons to v0te the moment they are out of prison regardless of uncompleted parole, probation, or restitution requirements. Section 2 of the Fourteenth Amendment gives states the constitutional authority to decide when felons who committed crimes against their fellow citizens may v0te again. Congress cannot override a constitutional amendment with a statute.
• Transfer the right to draw congressional districts from state legislatures to “independent” commissions whose members are unaccountable to v0ters. H.R. 0ne would make it a violation of federal law to engage in “partisan” redistricting and mandate the inclusion of alien population, both legal and illegal, in all redistricting. This is an anti-democratic, unconstitutional measure that would take away the ability of the citizens of a state to make their own decisions about redistricting.
• Authorize the Internal Revenue Service to engage in partisan activity. H.R. 0ne would permit the IRS to investigate and consider the political and policy positions of nonprofit organizations before granting tax-exempt status, thus enabling IRS officials to target organizations engaging in First Amendment activity with disfavored views.
• Limit access to federal courts for anyone challenging H.R. 1. The bill would prohibit the filing of any lawsuits challenging the constitutionality of H.R. 0ne anywhere except in the District Court for the District of Columbia and would allow the court to order all plaintiffs and intervenors, regardless of their number (such as all 50 states), “to file joint papers or to be represented by a single attorney at oral argument,” severely limiting the legal representation and due process rights of challengers.

I left out some of them, but there’s enough there that should scare you. This is the kind of thing that happened in 1930s socialist Germany to make sure that the secular left could not be challenged.