WASHINGTON — A key senator walks away from bipartisan budget talks. Congressional Republicans vote to end Medicare in its current form. Democrats spend nearly two weeks pushing to end oil company tax breaks, knowing their effort will fail.

Is Congress broken? Is it being held hostage by political extremes and therefore unable to reach agreement on anything? Is the legislative branch of government undergoing a historic change?

The evidence is inconclusive. Despite the stalemates, in recent months lawmakers have cut deals on tax reductions, a historic nuclear arms treaty and a budget-cutting plan that prevented a government shutdown.

Yet changes in the political culture are clearly adding great pressure, triggered by two interdependent forces: an inescapable news media and increasingly polarized views. Together they challenge congressional leaders' ability to broker the compromise essential to successful democratic government.

"Can you imagine writing the Constitution in today's environment?" asked Sen. Lindsey Graham, R-S.C. " 'Don't give in, Ben. Don't compromise, Tom.' You'd be met right outside Independence Hall by cable TV, (conservative commentator) Bill O'Reilly and (liberal) Rachel Maddow, and they're doing play-by-play.

"In today's world it's very hard for bipartisan agreements to be formed because those who don't like what you're trying to do are able to generate a lot of pushback early on. So this 24-hour news cycle makes it very, very difficult — but not impossible."

Gridlock could have serious consequences soon. The government reached its $14.3 trillion debt limit Monday, and its borrowing authority is expected to last only until Aug. 2, unless Congress raises it. Lawmakers also have until Sept. 30 to agree to a federal budget for fiscal 2012, which begins the next day.

Congress is particularly vulnerable to the 24/7 media world, because it's Washington's most open political institution. The Capitol and its offices are about the only federal buildings where reporters can generally roam free, walk up to elected officials and talk to them.

As a result, it's become a popular haven for bloggers, Tweeters and growing legions of reporters under pressure to feed the Internet and the ever-voracious media world. That means there's "no longer pause and effect," said Charles Bierbauer, the dean of the University of South Carolina journalism school and a former CNN anchor.

Nuances are not welcome in this media world, as members of Congress are wary of uttering a sentence that can instantly go viral and embarrass them. Witness the uproar over Newt Gingrich's single critical comment on the House GOP Medicare plan; some analysts think the conservative blowback at Gingrich could end his nascent presidential campaign.

"It's (information) no longer mediated," Bierbauer said. "Now you've provoked the guy on the other side of the aisle and you've gotten into turf battles which more likely would have been resolved in the cloak room in the good old days, rather than on Facebook. That's a larger problem than media itself."

A related part of the problem is the growing clout of ideologically inflexible political groups, who often react to any out-of-line utterances by politicians with quick and vicious outrage.

As a result, "there's less space for politicians to compromise and not have repercussions from it," said Steven Greene, an associate professor of political science at North Carolina State University.

For all the pressures of the modern era however, partisan gridlock is hardly new, and history shows that Congress' best shot at compromise comes near a deadline. December's agreement to extend the Bush-era tax cuts came just weeks before they were about to expire. Last month's budget-cutting deal was announced about 90 minutes before the government was to run out of money.

Brinksmanship is standard practice in Washington. The turmoil that most resembles the current situation was evident in 1995-96. Republicans won majorities of both houses of Congress in 1994 for the first time in 40 years and they vowed to change how government was run and funded.

At first they were as uncompromising as today's tea partiers. They faced Bill Clinton, a Democratic president, and a Senate where the Democratic minority was strong enough to block any GOP juggernaut. By late 1995, a partisan stalemate over the budget led to two extended government shutdowns.

Public outrage at that helped persuade both sides to compromise, and Clinton and the Republicans compromised again three times in the summer of 1996, on overhauling welfare, raising the minimum wage and making pensions portable. Both sides were trying to build a record of achievement before the November elections.

This year's next deadline on budget questions is Aug. 2, when the government no longer will be able to borrow money. Despite all the fiery rhetoric of late, there are small signs that deadline pressure again could force agreement.

When President Barack Obama announced the Biden-led talks last month, GOP leaders scoffed. But after a meeting May 12 with Obama, Senate Republican leader Mitch McConnell of Kentucky was more agreeable.

"Candidly, I was a little skeptical as to whether this meeting was worth having, but I actually think it was a very good meeting," he said. "We didn't have a big food fight in there over the things that we typically, you know, fight over in an election. I thought it was really helpful."

It's a start, though Graham knows it won't be easy.

"My statement to my colleagues is, even if people are loud, that doesn't mean they're the majority. So if you're doing things that make sense, just trust the country to figure it out," he said. "In this environment of constant media scrutiny, it's very difficult."