Dick Lugar's one-sided loss in last night's Indiana Republican primary is only the latest indication that this isn't your grandfather's Senate anymore. The days of "the World's Greatest Deliberative Body" are long gone. Bipartisanship a thing of the past. In fact, the man who ended Lugar's 35-year run in the Senate - State Treasurer Richard Mourdock - recently said that Washington's problem was "too much bipartisanship." Compare that to Lugar, who was held in such high esteem by his foes across the aisle that some Democrats even called his loss "a tragedy for the Senate."

 Out with the old and in with the new. In a scathing statement after his defeat, Lugar, the longest-tenured Republican senator, pulled no punches.

 "He and I share many positions," Lugar said of his victorious opponent, "but his embrace of an unrelenting partisan mindset is irreconcilable with my philosophy of governance and my experience of what brings results for Hoosiers in the Senate."

 "Unless he modifies his approach," Lugar warned, "he will achieve little as a legislator. Worse, he will help delay solutions that are totally beyond the capacity of partisan majorities to achieve."

 Mourdock joins a growing list of lawmakers propelled to victory by the Tea Party's anti-government, anti-tax movement. In the years since the Tea Party's 2010 success, Capitol Hill has become gripped by gridlock. Even the most basic task of Congress - to fund the government - has turned contentious. The government came    close to a federal shutdown last year - and more problems undoubtedly loom in the near future.

 Moderates like Lugar on both sides of the aisle are falling by the wayside. Only two months ago, Sen. Olympia Snowe, a Republican from Maine, announced her retirement, saying she was tired of the gridlock that has paralyzed Congress. When Snowe revealed her decision not to run for re-election, she said she found it "frustrating" that "an atmosphere of polarization and "my way or the highway" ideologies has become pervasive in campaigns and in our governing institutions." Snowe, one of only three Republicans to back President Obama's stimulus package in 2009, warned that it was "time for change in the way we govern" and emphasized the "vital need for the political center" but said she was not optimistic about the future.

"Unfortunately, I do not realistically expect the partisanship of recent years in the Senate to change over the short term," Snowe said.

It is not only Republican moderates who are becoming extinct on Capitol Hill. Democratic Sens. Jim Webb of Virginia and Kent Conrad of North Dakota are retiring this year, too. Other moderates who have decided to fight for re-election, as evidenced by Lugar's loss, have a hard fight ahead.

 Crossing the aisle, it seems, is something people used to do in the good ole days. A sign of things to come could be seen on the Senate floor on the day of Lugar's loss when an attempt to prevent student loan rates from doubling this summer went down in defeat. The measure did not even gain enough votes to undergo debate in the esteemed upper chamber of Congress.

 That made the goings-on 350 miles to the north seem especially pointless. In Albany, N.Y.,   Obama was busy outlining a "to-do list" for Congress to accomplish over the coming months.

 "I know this is an election year, but it's not an excuse for inaction," he said. "Six months is plenty of time for Democrats and Republicans to get together and do the right thing."

 Of course, Obama, a former senator himself, knows perfectly well that "getting together" and "doing the right thing" are just about the last things anyone in Congress cares about these days.  His own "to-do list" was merely an exercise in political mockery.

 For both Democrats and Republicans alike, that is sadly what Congress has become: a dysfunctional object of derision. With moderate lawmakers like Lugar, Snowe, Conrad and others on their way out of town, the polarization on Capitol Hill is now  likely only to increase.

While the nostalgia about what Congress used to be is frequently overblown - the people who sang its praises the most were always the lawmakers themselves - the recent gridlock could start to prove problematic for the country in the coming years. More partisanship. More filibusters. More secret holds.

 Maybe the Senate, even in its heyday, never was "the World's Greatest Deliberate Body," but now, it appears, it won't be able to lay claim to that title anytime soon.

  Matthew Jaffe covers the 2012 campaign for ABC News and Univision.