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Republican senators are still sorting out how to accomplish their goal of repealing and replacing the Affordable Care Act. Proposed strategies this week have been all over the place — passing GOP senators’ Better Care Reconciliation Act, doing nothing and letting Obamacare fail, and repealing the ACA and replacing it later. These are very different policy moves that would have very different effects on the health insurance landscape. But all of them have one thing in common: They assume the private insurance marketplaces set up under the Affordable Care Act continue to provide coverage through 2018. But there are at least three key decisions the Trump administration has to make that could affect what that looks like.

Insurers in most states have submitted proposals for the insurance plans they want to sell in 2018. Those plans are being negotiated and reviewed. According to data compiled by Charles Gaba at ACASignups.net, an independent tracker who supports the ACA, there may be an average 33 percent increase in premiums next year (before subsidies), and around 20 percent of that is due to uncertainty created by the current administration. Although negotiations are ongoing and some states have yet to reveal proposals, those estimates square with statements from insurers and health policy experts. A national average, however, masks huge variations by state: For example, insurers in Vermont and Oregon are seeking relatively small premium increases, while people in New Mexico and Georgia could see steep increases.

There are a variety of reasons for these increases. One is that it’s not clear whether the Trump administration will enforce the mandate that most people have health insurance or pay a fine, though it has already weakened it, which could mean fewer healthy people participating in the marketplaces and higher premiums for those who do. Another is that we don’t know whether President Trump will use marketing and advertising to promote enrollment as the Obama administration did, which has been shown to increase enrollment among healthier people. There are already signs he will not: The Daily Beast reported that the Department of Health and Human Services has been using money earmarked to promote enrollment to create videos attacking Obamacare. And Politico reported that the department canceled contracts with two companies that were supposed to help enroll people during the open enrollment period for next year. Again, fewer healthier people in the marketplaces results in higher premiums.

The other big outstanding question is how Trump and Congress will deal with payments owed to health insurance companies. Insurers are required to give the poorest enrollees discounts on things like deductibles and co-pays; the law intended for the federal government to reimburse those discounts — with Congress appropriating the funds. When Congress refused to do so, Obama made the payments anyway, and Congress sued his administration. (The court case is ongoing.) Trump has been making the payments on a month-by-month basis while threatening to pull them, using the payments as leverage in the ongoing repeal debate in Congress. More than half of people using the marketplaces receive these payments; if insurers aren’t reimbursed, it will push up premiums and could lead some to leave the marketplace.

What the administration does with these three things will help determine premiums for next year, which will also determine who can afford coverage and how much the federal government spends in subsidies. We’ve written about uncertainty and the markets before at TrumpBeat, but it’s worth bearing in mind that the ongoing debate in Congress affects not only future legislation, but also existing law.

Voting integrity: ID check

The 1993 National Voter Registration Act was aimed at making it easier for more Americans to vote by coupling registration opportunities with driver’s license and public assistance applications and making it harder to kick registered voters off the rolls. Now there’s evidence that Kris Kobach, the vice chairman of Trump’s new Presidential Advisory Commission on Election Integrity, wants to change that law.

In emails that were released last week as part of a lawsuit brought against him by the American Civil Liberties Union, Kobach wrote of planned legislation that would amend the National Voter Registration Act so that it explicitly allows states to require proof of citizenship — a passport or a birth certificate — for a voter to register. That news has only added fodder for the chorus of criticism aimed at Kobach and his commission.

We’ve written previously about the many problems with Kobach’s claims of widespread voter fraud. The short version: Nobody knows exactly how much illegal voting occurs, but all the available data points to it being extremely rare. Interestingly, though, it’s just as hard to prove the negative effects of the voter ID laws Kobach has championed.

As with illegal voting, it’s difficult to study voter ID laws, and nobody knows for sure whether they reduce turnout — effectively suppressing legal votes. No two states have exactly the same laws, and most of the laws have been in effect for less than five years. Maybe most importantly, there are confounding factors that make it difficult to tease apart cause and effect — for instance, the states that had adopted a strict voter ID law by 2015 already had lower voter turnout than those that did not. That comes from an analysis of peer-reviewed research on this topic published in May by Benjamin Highton, a political scientist at the University of California, Davis. He found just four studies that were designed to account for these kinds of real-world problems; all came up with results that suggest ID laws have very limited impacts (less than 4 percentage points) on voter turnout.

This is unlikely to be the final word on the subject, of course. Scientifically, this question is at the starting gate, not the finish line. But it’s possible that American politics is currently fighting a heated partisan battle over two risks — voter fraud and ID-law-related voter suppression — that are both extremely small.

Immigration: Opening the door

A central plank of Trump’s “America First” campaign platform was a pledge to limit immigration: He vowed to crack down on both illegal immigration and abuse of guest-worker programs that, Trump argued, push down wages for American workers. Since taking office, Trump has stuck with his “hire American” rhetoric, signing an executive order that tightened rules on visas for foreign workers and pledging to overhaul the legal immigration system

This week, however, Trump’s Department of Homeland Security said it would increase the number of visas for workers in low-wage industries that rely on temporary employees. The department announced that it was adding 15,000 H-2B visas for workers in seasonal, nonagricultural jobs, a 45 percent increase from what is normally issued for the second half of the fiscal year.

The H-2B announcement scrambled the usual politics of immigration. Business groups, which have often expressed concern about Trump’s hostility to immigration, praised the decision, saying that they need temporary foreign workers to fill labor shortages in the hospitality, construction and seafood industries. Meanwhile, the Center for Immigration Studies, an independent research organization that advocates for limited immigration, criticized the move, which it argued takes jobs away from a pool of U.S. workers. (The group noted that the White House declared this “Made in America” week and highlighted the administration’s hire-American policies.)

In its announcement, the Department of Homeland Security noted that businesses only qualify for the visas if they can prove that they are likely to “suffer irreparable harm” if unable to hire foreign workers. But critics are skeptical that labor shortages are as severe as companies claim. The Economic Policy Institute, a liberal think tank that Trump has aligned himself with on certain issues, argued in a recent report that almost all of the top 10 occupations for H-2B workers have relatively high unemployment rates and have experienced stagnant or declining wages since 2004. That, the group argues, suggests there is no shortage of available workers, at least on a national level. (The report does note that it is possible that states and local areas are experiencing a limited labor pool for these jobs but claims the H-2B program maintains a framework that exploits foreign workers.)

It isn’t clear why Trump agreed to increase the H-2B program even as his administration is cracking down on visas available to skilled workers in areas such as tech and limiting other routes of legal immigration. But it’s worth noting that Trump himself has used H2-B visas in the past to hire temporary workers for his resorts and hotels and even remarked on the difficulties of hiring part-time workers during a debate last year.