WASHINGTON — House Democrats on Wednesday unveiled an immigration bill that provides a path to citizenship for the 11 million immigrants living here illegally and tightens border security, and they warned of political fallout if House Republicans fail to act.

Minority Leader Nancy Pelosi, D-Calif., and more than a dozen Democrats said they were ready to move on overhauling the nation's immigration system. Their bill combines major elements of a bill the Senate passed in June with bipartisan border security legislation that won unanimous support in the Homeland Security Committee in May.

Speaking in English and Spanish, Rep. Joe Garcia, D-Fla., said the legislation wasn't perfect but urged Republicans to back the measure.

"Republicans like Ronald Reagan and George Bush to John McCain championed immigration reform," Garcia told reporters at a Capitol Hill news conference. "There is no reason why our Republican colleagues cannot follow their lead and their footsteps to pass a comprehensive immigration bill."

Most House Republicans reject a comprehensive approach and many question offering citizenship to people who broke U.S. immigration laws to be in this country. The House Judiciary Committee has moved forward with individual, single-issue immigration bills.

Although House Republican leaders say they want to solve the issue, which has become a political drag for the GOP, many rank-and-file House Republicans have shown little inclination to deal with it.

The contentious issue of immigration was on the backburner even before the budget standoff largely paralyzed Congress. A hearing in the House Judiciary Committee on the issue scheduled for Tuesday was postponed on what turned out to be the first day of the government shutdown.

Even more so now, it's unclear whether the GOP-led House will ever pass legislation that could form the basis for a final deal with the Democratic-controlled Senate.

House Democrats strongly signaled that the absence of legislation could instead be a political issue.

Rep. Joaquin Castro, D-Texas, highlighted the unusual coalition of evangelicals, business and labor favoring immigration legislation.

"If it doesn't happen, it's really a failure of House Republicans to listen to the American people to take action," Castro said.

The Senate bill, strongly backed by the White House, includes billions for border security, a reworked legal immigration system to allow tens of thousands of high- and low-skilled workers into the country, and a 13-year path to citizenship for the 11 million immigrants already here illegally.

The bill from House Democrats jettisoned the border security provision and replaces it with the Homeland panel's version. That bill, backed by conservative Republicans and liberal Democrats, would require the secretary of Homeland Security to develop a strategy to gain operational control of the border within five years and a plan to implement the strategy. It calls on the Government Accountability Office to oversee the steps being taken.

The bill doesn't call for new spending, in contrast to the Senate bill with $46 billion in new spending on drones, helicopters and other technology, a doubling of agents patrolling the border with Mexico and hundreds of miles of new fencing.

Pelosi said the House Democrats' bill is "not a challenge" to Speaker John Boehner, R-Ohio, but rather a "suggestion."

Rep. Steve Horsford, D-Nev., expressed the hope that the "toxic obstruction" in Washington wouldn't kill the chances for immigration legislation.