The rise of Bernie Sanders as a policy force among liberals has forced Hillary Clinton to lurch left this presidential primary season, from opposing the Trans-Pacific Partnership and the Keystone XL pipeline to calling for a repeal of the “Cadillac tax” on high-cost health care plans. Now she’s cobbled together a plan to protect and advance reforms of the financial industry. 

Clinton’s plan does not go as far as Sanders’ or her other rivals’—there’s no proposal to reconstitute the firewall between investment and commercial banking, for example. What Clinton does endorse addresses some glaring problems in the financial system: opaque algorithmic trading, risky bets with depositor funds, and bank executives who evade justice when they break the law. Whether you think they will work depends on how you game out the likely responses to such changes. 

For example, Clinton wants to strengthen the Volcker rule, the kludgy step-sister to Glass-Steagall, the investment/commercial bank firewall. The Volcker rule, named for the former Federal Reserve chair, is designed to prevent deposit-taking banks from making proprietary trades with their own funds. But it included several loopholes, including one allowing banks to invest up to three percent of their capital in hedge funds, who then make those trades. Banks haven’t even needed to sell their other stakes in hedge funds and private equity firms to get under that limit. And Goldman Sachs, in particular, has been testing the Volcker rule by redeploying money that used to fund hedge funds and buying the underlying investments outright (known as merchant banking). 

Clinton wants to close the hedge fund loophole, disallowing any stakes by deposit-taking banks, and ensuring that the broadest possible definition of “hedge fund” is used to prevent regulatory gaming. But it’s not clear that this would stop Goldman’s merchant banking activity, which could wind up even riskier, because more of their own money is at stake. In fact, restricting the hedge fund stakes could lead other banks to copycat Goldman’s efforts. 

Another area where the technocratic impulse could lead to unintended consequences comes with a proposed tax on high frequency trading (HFT). This rapid-fire trading done through computer algorithms takes up an increasing percentage of stock trades, with money being skimmed off very small fluctuations in price.

Clinton’s tax is intended to attack one type of HFT known as “spoofing,” where the trader feigns interest in a security to run up the price and then cancels the orders after selling their position. The tax, which does not have a defined rate yet, would “hit HFT strategies involving excessive levels of order cancellations,” according to the campaign’s memo on her plans.

This seems extremely easy to game, says economist Dean Baker. “If the tax is on cancelled orders then I can envision that you have arrangements with exchanges where orders are modified, but not cancelled,” he said. Algorithmic traders could also pick what markets and exchanges to probe to avoid the tax and get the information they need to make their profits, Baker added. “As a general rule, this sort of micro-managing of financial markets is almost guaranteed to fail.” 

Moreover, the federal government has virtually no usable data on algorithmic trades, and would be hard-pressed to enforce one part of the market relative to the other while identifying shifts to evade regulation. The Commodity Futures Trading Commission has to police the entire multi-trillion-dollar derivative market with a tiny staff and budget. Detecting changes in strategies doesn’t happen unless by accident.

By contrast, a small financial transactions tax on all trades overlays a big prescription over the entire market, which would be infinitesimal for normal traders but a heavy burden for HFT, potentially causing the desired effect of less trading. Regulations that create full employment acts for lawyers and compliance officers to find the loopholes work far less well than structural alterations that cannot be gamed.

Some of Clinton’s plans recognize this. She would reinstate the swaps push-out rule, which Republicans successfully repealed at the end of last year. This would keep all derivatives trades in separately capitalized entities, rather than forcing regulators to pick and choose what derivatives should fall where. Her “risk fee” on banks with over $50 billion in assets and other systemically important financial institutions, which imposes higher costs on those who fund their activities with more debt, could help pay for systemic problems while reducing leverage in the system. And she reiterates regulatory authority within Dodd-Frank to break up banks if they cannot prove they can be managed and wound down effectively. 

Clinton also builds on the “Yates memo” guidance from the Justice Department last month, which proposed holding individuals accountable for financial fraud. But she goes further than that, by permitting the claw-back of executive bonuses to pay for corporate fines, empowering regulators to force top executives to leave their jobs when crime happens on their watch, prohibiting anyone convicted of financial fraud from ever working on Wall Street again, and extending the statute of limitations on financial fraud to 10 years, giving law enforcement more time to develop cases. “More aggressively going after individuals versus institutions has the potential to discourage reckless dealings with other people’s money,” said Jared Bernstein of the Center on Budget and Policy Priorities. 

The full plan, if diligently enforced, could prevent some activities that brought our economy to the brink in 2008. But the operative phrase is “if diligently enforced.” You can write as many new restrictions as you want, but you must have individual regulators willing to be aggressive and creative to get the job done. “As we all know, personnel is policy,” said Jeff Connaughton, chief of staff to former Senator Ted Kaufman and a persistent critic of current efforts to reform Wall Street. “Who will appoint trial lawyers with blood in their eyes to DoJ? Or reformers with a track record as top regulators?” 

We know that Gary Gensler, the Clinton campaign’s chief financial officer and a fairly good regulator as chair of the Commodity Futures Trading Commission under Obama, helped shape the Wall Street reform plans. So did former Congressman Barney Frank, architect of Dodd-Frank, which most critics see as a good but ultimately inadequate set of reforms. Clinton, in another case of her hand being forced by campaign politics, has vowed to stop the “revolving door” between Washington and Wall Street. But will she meet that test? 

“Ultimately,” Connaughton said, “my view is it’s more than what a candidate proposes, it’s whom do you trust to mean what they say?”