WASHINGTON — While President Obama was promoting an immigration overhaul in Mexico, six former members of Congress gathered two blocks from the White House to consider what they see as the enforced government secrecy surrounding another kind of visitor: the kind who come from a lot farther away.

Every day this week, the former legislators presided over panels made up of academics and — former, of course — government and military officials, who were there to discuss their research or their own eyewitness accounts of unidentified flying objects and the extraterrestrials who presumably would have occupied them.

“Something is monitoring the planet, and they are monitoring it very cautiously, because we are a very warlike planet,” said Mike Gravel, a former Democratic senator from Alaska who ran in both the Democratic and Libertarian presidential primaries in 2008.

Mr. Gravel and his fellow panelists were assembled by the Paradigm Research Group, which says it is committed to ending the government’s “truth embargo” on the existence of extraterrestrial life. The lawmakers were there in hopes that their presence and political credibility would be enough to persuade Congress to take the issue seriously.