Late on Monday evening, when Barack Obama urged citizens who agree with his “balanced approach” on deficits and debt to “let your Member of Congress know” and “send that message,” most observers surely expected a mild reaction with some of the president’s staunch supporters calling in to support their man.

What Washington got instead was electronic mayhem, as phone lines jammed, House websites crashed, and the vaunted Obama grassroots network that made so much noise in 2008 — and so little since – suddenly roared to life:

The Chief Administrative Officer of the Capitol alerted the House in an email Tuesday morning that House telephone circuits were near capacity due to a high volume of external calls. Congressional offices were advised to give their staff outside of the capitol and other key contacts an alternate number to call.

Multiple congressional websites crashed or slowed down last night after they were inundated with visitors.

Meanwhile, Obama’s pleas for compromise – and his endorsement of Senate Majority Leader Harry Reid’s $2.7 trillion, no-revenue, debt-increase bill – were bolstered by a report that the nation’s AAA credit rating cannot be preserved with any other legislation at this point. Making her CNN debut, business correspondent Erin Burnett told viewers that Reid’s plan probably would prevent an immediate downgrade of US Treasury bonds (and an explosion of higher interest rates), while the proposal floated by House Speaker John Boehner “probably wouldn’t hit the hurdle to prevent a downgrade.” Burnett — a former star at CNBC, the business network where the Tea Party movement was born in 2009 with an outburst from Rick Santelli — quoted a source who recently met with officials at Standard & Poor’s, the nation’s largest rating agency.

As citizen pressure mounted for a debt limit increase today, activists sought to prevent a technological logjam from stopping voters from reaching their representatives. Americans United For Change, a group focused on defending Social Security and Medicare, introduced an online tool that allows constituents to enter notes and have them faxed directly to a congressman’s office. Lauren Weiner, its communications director, said on Tuesday afternoon that her group had sent over 10,000 faxes.

The Progressive Change Campaign Committee (PCCC), an Internet-based grassroots group, urged its members to physically appear at their lawmakers’ offices, Twitter be damned.

“Given the fact that the switchboards are melting down, [we’re encouraging members to] stop by their local congressional office. [Rep.] Paul Ryan’s office in Kenosha had 40 or 50 people show up to protest proposed cuts in Medicare and Social Security benefits,” Neil Sroka, press secretary for PCCC, said Tuesday afternoon.

Of course, with scores of conservative Republicans indicating they won’t support their own Speaker’s proposal, the path forward to a debt-limit increase remains unclear. The Democrats — and Republicans who fear default’s economic and political consequences – will somehow need to muster 218 votes, the margin needed to pass a bill through a House of Representatives that still seems dominated by the ideology of the Tea Party.