Many strange things are afoot up in Washington, the latest being U.S. Rep. John Lewis leading his fellow House Democrats in a sit-in of the House chambers Wednesday night and into Thursday, protesting Republican refusal to allow votes on rather mild gun-control measures.

Such a takeover is unprecedented, but what's really interesting is the issue that precipitated it. For years, a lot of Democrats cowered in fear at the prospect of having to take a vote on gun-control bills, considering it a no-win proposition. Now they're going to extraordinary measures -- including a filibuster last week in the Senate -- to demand the right to be heard on such issues, while Republicans are clearly on the defensive.

Yes, part of that's attributable to the recent mass shooting in Orlando, as well as the recognition that in the week after that shooting -- a week much like any other in this country -- another 500 Americans were killed or wounded with firearms. Gun-safety advocates have long had the polling numbers on their side -- in a new Morning Consult poll, 68 percent of Americans and 57 percent of Republicans said they would support banning assault weapons -- but they failed because they could never match the emotional intensity of the NRA and others opposed to such regulations.

That might now be changing.

However, I suspect that what we're seeing goes well beyond the gun-control issue. When Democrats look at their opposition these days, they see a badly divided party led by the likes of Donald Trump, with some Republicans still muttering about a contested convention in Cleveland. They see Hillary Clinton raising tens of millions of dollars for the general election campaign and putting campaign staff in every one of the 50 states, eying red-state opportunities such as Georgia and Arizona. On the other side they see Trump with a smaller campaign chest than many House members, still struggling to hire staff even in the swing states.

They look to the crucial state of Florida, where Sen. Marco Rubio announced his re-election bid this week with an explicit repudiation of his own party's nominee. They see other Republican politicians fearful of even uttering the name of their presidential nominee, and Wall Street and corporate America fleeing from any association with the GOP.  They watch the job approval ratings for President Obama -- a man the Republicans have slimed for years as little short of a traitor -- rising to levels exceeding those of Ronald Reagan at the same point in his presidency, and they note that just 30 percent of voters approve of the GOP's performance. (Their own job-approval rating averages 45 percent.)

They know that the social issues that Republicans long used to their advantage have now become big burdens for the GOP, and that Trump's bigoted rhetoric has set back the Republican outreach to minority voters for a generation or more. They see that income inequality, an issue that Republicans used to haughtily dismiss as "the politics of envy," is now high on the agenda for both parties, and they can't help but observe that the primary GOP solution remains more tax cuts for the wealthy, an approach not likely to find traction. The surprising and message-driven success of Bernie Sanders and the popularity of Elizabeth Warren have also not gone unnoticed.

Traditionally, a sit-in is the tactic of the weak and powerless, attempting to turn that weakness into a form of strength. I don't think that's the case this time.

This time, it's an expression of growing confidence and of a belief that the ice that has long bound the American political system might finally be breaking.  It's an indication that Democrats have lost their fear of the Republicans, and that for the moment at least, the Republicans are too confused and divided to do much about it.