It looks like the Steve King/ Tea Party anti-Amnesty/ Immigration Surge demonstration worked despite Washington Watcher's fears:

Sen. Marco Rubio (R-Fla.) is feeling the heat as potential GOP allies are now turning against his immigration reform bill.

Republican colleagues who were previously viewed as possible “yes” votes are keeping their distance from the 1,075-page measure.

On Wednesday, conservative activists ripped Rubio and Sen. John McCain (R-Ariz.) — both sponsors of the bipartisan immigration measure — at a Capitol Hill rally.

The crowd, which was protesting the bill’s effort to put millions of illegal immigrants on a path to citizenship, booed at the mention of Rubio’s name during the six-hour event.

The rally underscored the mounting opposition to the immigration reform bill among both grassroots conservatives and GOP senators.

Right rips Rubio as Republican immigration votes slip away, by Alexander Bolton, June 19, 2013. (Emphases added throughout).

 The article continues:

Potential Senate Republican backing for the legislation has begun to evaporate because of deep skepticism over its border-security and enforcement provisions.

In recent weeks, senators on both sides of the aisle speculated that 70 members of the upper chamber might vote for the Senate bill. That tally is now seen as unattainable.

Republican Sens. Mitch McConnell (Ky.), Rand Paul (Ky.) and John Cornyn (Texas), who were once viewed as possible supporters of the bill, are now expected to reject it.

Of course, there's a certain amount of theater in this—these rats could have killed the bill at the cloture vote last Thursday—but it's a good sign.