Voters are forever being told that they face stark choices. But the platform that Democrats approved Tuesday at their convention in Charlotte, N.C., was, in areas from social issues to entitlements, a mirror image of the platform that the Republicans adopted last week in Tampa, Fla.


Yet it was the omission of something that had been included in Democratic Party platforms since at least 1992 — a statement that Jerusalem is the capital of Israel — that drew immediate criticism from Republicans.


The Democratic platform supports same-sex marriage for the first time — “We support marriage equality and support the movement to secure equal treatment under law for same-sex couples,” it reads — and reaffirms the party’s support for abortion rights. The Republican platform supports the passage of constitutional amendments that would ban abortion and define marriage as “the union of one man and one woman.”


When it comes to Medicare, the Democratic platform says the party will oppose “any efforts to privatize or voucherize” the program, while the Republican platform would reshape the program for those under 55 so they would get “an income-adjusted contribution toward a health plan of the enrollee’s choice,” including a government plan.


And while the Democratic platform opposes any privatization of Social Security, the Republican platform says younger workers should be given the option of “personal investment accounts as supplements to the system.”


But it was the absence of the plank on Jerusalem that drew criticism from Mitt Romney, the Republican presidential nominee.


The new Democratic platform states that “President Obama and the Democratic Party maintain an unshakable commitment to Israel’s security,” but drops language from previous platforms about Jerusalem. The 2008 platform said: “Jerusalem is and will remain the capital of Israel. The parties have agreed that Jerusalem is a matter for final status negotiations. It should remain an undivided city accessible to people of all faiths.”


Obama administration officials, in keeping with decades of official American policy, have been unwilling call Jerusalem the capital of Israel because Palestinians also envision it as the future capital of their hoped-for state.


Mr. Romney issued a statement Tuesday criticizing the platform’s omission as “shameful.”


If there is one thing the two parties agree on this year, it is the size of the chasm that divides them on so many issues. The Democratic platform says that “this election is not simply a choice between two candidates or two political parties, but between two fundamentally different paths for our country and our families.” The Republican platform calls the 2012 elections “a referendum on the future of liberty in America.”


Mayor Cory A. Booker of Newark, a platform committee chairman, emphasized its call for a “balanced approach” to deficit reduction, including raising taxes on the wealthy. “When your country is in a costly war, with our soldiers sacrificing abroad, and our nation is facing a debt crisis at home, being asked to pay your fair share isn’t class warfare,” he said. “It’s patriotism.”


The Democratic platform sometimes reads more like a look back than a road map of what the party would do over the next four years. Many paragraphs are devoted to putting President Obama’s record in the most flattering light possible. The platform mentions that 4.5 million private-sector jobs have been created in the United States since “early 2010” — a time period that ignores the steep job losses of 2009. If the platform had started counting in January 2009, the month Mr. Obama took office, it would have found that 332,000 private-sector jobs had been created.


Some of this year’s planks are reminders of the unfulfilled pledges from 2008.


That platform, echoing a promise Mr. Obama had made as a candidate, said, “We will close the detention camp in Guantánamo Bay, the location of so many of the worst constitutional abuses in recent years.” As president, though, Mr. Obama has failed to deliver on that promise, so the 2012 platform says “we are substantially reducing the population at Guantánamo Bay.”


The 2008 platform called for “comprehensive immigration reform,” but since it has not passed, the 2012 platform does, too. And the 2008 platform said “we will implement a market-based cap-and-trade system to reduce carbon emissions by the amount scientists say is necessary to avoid catastrophic change.” Since that has not happened, the 2012 platform calls for reducing carbon emissions domestically “through regulation and market solutions.”


But any tension between the party’s last platform and its current platform pales in comparison with the differences between the Democratic and Republican party platforms this year.


While the Democrats failed to enact the promised climate change legislation, they still call it a top priority. “We know that global climate change is one of the biggest threats of this generation — an economic, environmental and national security catastrophe in the making,” their platform says, adding that they “affirm the science of climate change.”


This year’s Republican platform dropped the 2008 section on “addressing climate change responsibly.” The new platform states that it opposes “any and all cap-and-trade legislation.”


The Democratic platform says “the right to organize and collectively bargain is a fundamental American value” and opposes “the attacks on collective bargaining that Republican governors and state legislatures are mounting in states around the country.” The Republicans support right-to-work laws, which weaken unions, and salute “the Republican governors and state legislators who have saved their states from fiscal disaster by reforming their laws governing public employee unions.”


On taxes, the Democratic platform says that President Obama will fight to extend tax cuts for the middle class while “asking the wealthiest and corporations to pay their fair share.” The Republican platform calls for extending the Bush-era tax cuts.


And on guns, the Democratic platform states that “the individual right to bear arms is an important part of the American tradition, and we will preserve Americans’ Second Amendment right to own and use firearms.” But it says the right can be subject to “reasonable regulation,” and calls for reinstating the assault weapons ban. The Republican platform says, “We oppose legislation that is intended to restrict our Second Amendment rights by limiting the capacity of clips or magazines or otherwise restoring the ill-considered Clinton gun ban.”