WASHINGTON | For Senate Republicans, 2012 is starting a lot like 2010.

They have a shot at taking control away from Democrats as long as insurgent conservatives who are defeating the party's more establishment candidates in primaries don't frighten too many independent voters like they did two years ago.

Deb Fischer, a little-known state senator, became the latest unexpected Senate GOP nominee Tuesday, rallying late to upset the favored ? and better funded ? choices of both the party's mainstream and tea party establishments: Nebraska Attorney General Jon Bruning and state Treasurer Don Stenberg.

Her victory occurred just a week after tea party and other conservative groups embraced Indiana state Treasurer Richard Mourdock, who scored an arguably bigger upset ? knocking off six-term Sen. Richard Lugar, the Senate's longest-serving Republican.

The message for the GOP: Insurgents are back.

What's yet to become clear is whether they exemplify 2010's class of conservative upstarts ? Florida's Marco Rubio, Kentucky's Rand Paul, Utah's Mike Lee and Wisconsin's Ron Johnson.