WASHINGTON — From simple home loans to Wall Street’s most exotic schemes, the government would impose and enforce sweeping new “rules of the road” for the nation’s battered financial system under an overhaul proposed Wednesday by President Barack Obama.

Aimed at preventing a repeat of the worst economic crisis in seven decades, the changes would begin to reverse a determined campaign pressed in the 1980s by President Ronald Reagan to cut back on federal regulations.

Obama’s plan would do little to streamline the alphabet soup of agencies that oversee the financial sector. But it calls for fundamental shifts in authority that would eliminate one regulatory agency, create another and both enhance and undercut the authority of the powerful Federal Reserve.

The new agency, a consumer protection office, would specifically take over oversight of mortgages, requiring that lenders give customers the option of “plain vanilla” plans with straightforward and affordable terms.

Lenders who repackage loans and sell them to investors as securities would be required to retain 5 percent of the credit risk — a figure some analysts believe is too low.

In all, Obama’s broad proposal cheered consumer advocates and dismayed the banking industry with its proposed creation of a regulator to protect consumers in all their banking transactions, from mortgages to credit cards. Large insurers protested the administration’s decision not to impose a standard, federal regulation on the insurance industry, leaving it to states.

Mutual funds succeeded in staying under the jurisdiction of the Securities and Exchange Commission.

Obama cast his proposals as an attempt to find a middle ground between the benefits and excesses of capitalism.

“We are called upon to put in place those reforms that allow our best qualities to flourish — while keeping those worst traits in check,” Obama said.

The president’s plan now goes to Congress.

Obama has set an ambitious schedule, pushing lawmakers to adopt a new regulatory regime by year’s end.