WASHINGTON – It might seem a recipe for success: Legislation to help small businesses raise capital passed the House last week with 95 percent of lawmakers voting for it and President Obama’s support. But in today’s Congress, nothing comes easy.

Since the House vote, a senior official in the Obama administration has voiced concerns that the bill would weaken protections for would-be investors in startup companies. Now that the bill is on the Senate floor, Democratic opponents are warning of repeats of the Enron and dot-com debacles.

Also complicating the legislation’s prospects is a Democratic attempt to link it to extending the Export-Import Bank and expanding the amount of money it can lend. Some conservatives would like to eliminate the agency.

“They want to pick a fight rather than get this bill to the president’s desk,” Senate Republican leader Mitch McConnell of Kentucky said Thursday of the Democratic moves.

The bill’s Republican promoters in the House refer to it as the JOBS Act. It would exempt small businesses and startups from some Securities and Exchange Commission regulations, making it easier and less costly for them to raise capital and go public.

Among the six smaller bills combined in the House package, one creates a new emerging growth company classification that phases in SEC regulations over five years. Another removes SEC restrictions on “crowdfunding,” the raising of capital from a larger pool of small-scale investors.

Both the White House and lawmakers welcomed the steps as ways to remove red tape and thus lead to job creation.

But SEC Chairman Mary Shapiro this week presented Senate Banking Committee leaders with a list of concerns. The bill’s definition of an emerging growth company is so broad “that it would eliminate important protections for investors in even very large companies, including those with up to $1 billion in annual revenue,” she said.

Shapiro also said the provision on crowdfunding “needs additional safeguards to protect investors from those who may seek to engage in fraudulent activities.”

Sen. Dick Durbin of Illinois, the second-ranking Senate Democrat, was more direct: “Let’s call this crowdfunding for what it is. It is Internet gambling, and the odds will never favor the investor.”

He said the “so-called jobs bill creates a job opportunity for any individual salesman to set up shop with a barstool and a laptop computer.”

“They can be selling worthless stock for phantom companies,” Durbin said.

Supporters of the crowdfunding provision, which allows companies to raise up to $1 million a year through registered Internet websites, insist it provides adequate investor protections.

But the Coalition for Sensible Safeguards, an alliance of normally Obama-friendly labor, good-government and consumer advocacy groups, are urging the bill’s defeat. “This ill-advised measure would roll back financial safeguards that were put in place to prevent the kind of fraud and abuse we saw during the Enron scandal, the dot-com bust and the recent mortgage meltdown and financial collapse,” it said.

White House press spokeswoman Amy Brundage, in a statement Wednesday, repeated that there were numerous elements of the legislation that Obama had espoused as part of his proposals to help small businesses. But she added that Obama supports efforts by Senate Democrats to both find common ground with the House bill “while also improving the House bill to ensure there are sufficient safeguards to prevent abuse and protect investors.”

She added that the White House supports reauthorization of the Export-Import Bank.

Senate Majority Leader Harry Reid announced Thursday that the Senate will vote Tuesday on whether to take up two amendments dealing with investor protections and the bank. Both would require 60 votes to advance. The investor protection measure, backed by Durbin, is likely to face strong GOP resistance and be voted down.