There did seem to be something off as the senators left the headquarters of the National Republican Senatorial Committee (NRSC) Tuesday.

An unidentified NRSC staffer had come out of the building and jokingly referred to me as a “tracker”–a term given to campaign operatives who film their opponents, hoping to capture every gaffe. “We know who you are,” the staffer said.

Leaving the building, Sen. Tom Coburn (R-OK), although declining to answer questions, furtively offered an unusual sentiment: “Go Breitbart!” he said. Senate Minority Leader Mitch McConnell seemed to glare at me, and his colleagues were a bit more reticent to talk than usual.

As it turns out, they had been warned, specifically, about me.

The subject of the email, obtained by Breitbart News, was “Press Outside RPC Lunch @ NRSC.” Sent by Lisa Kramer, it read: “All–Todd has asked that I email to let you know that Matt Boyle with Breitbart is currently outside the NRSC. We have our Press Secretary outside, and there is no issue; just wanted to give you a heads up.”

Kramer is the assistant to NRSC executive director Rob Collins, and “Todd,” to whom she refers in the email, is Todd Novascone, a staffer for NRSC Chairman Sen. Jerry Moran (R-KS). Novascone was cc’ed on the email, and the full list to which it was sent–which include Senate chiefs of staff and other key staffers, and perhaps U.S. senators themselves–was blind.

Notably, many of the senators emerging from the NRSC building did take my questions, despite the warning. Sens. Rob Portman (R-OH), Rand Paul (R-KY), and Roger Wicker (R-MS) all conducted brief interviews without incident.

But the last time I was staking out the NRSC building, senators were lining up to help Sen. Thad Cochran (R-MS) raise over $800,000, money that went to Cochran’s campaign, which we know now distributed bundles of cash to Democratic “get out the vote” operations and faces allegations of vote-buying. A super PAC backing Cochran has admitted to paying for incendiary race-baiting ads targeted at Democratic voters that pitched a Cochran vote as a means of stopping the racist Tea Party.

In that sense, you can imagine they might not want to answer tough questions. It’s worth mentioning that senators are public servants. Taxpayers pay their salaries, and they are accountable to voters. I wasn’t loitering outside a private country club.

And, as the email shows, U.S. senators should be smart enough to know: you can run, but you can’t hide.