Lisa Wilson-Foley, a businesswoman who ran for lieutenant governor last year, has formally joined the Republican field in the race to replace Rep. Christopher Murphy (D), who is running for Senate, in 2012.

Republicans believe the 5th district is a legitimate pickup opportunity, even in a state where the GOP has a massive voter registration disadvantage.

“What do you do when the government has pushed you to a point where you simply say, ‘I’ve had enough?’ My answer is this — you fight,” Wilson-Foley said in the Tuesday statement announcing her candidacy. “You fight to take back what is yours — your rights, your money, your freedom — our future. That is why I have announced my candidacy.”

The announcement notes the support of a state Senator and the hiring of the same spokeswoman who handled media for Republican Sam Caligiuri’s unsuccessful run for Congress last year.

The GOP primary will include at least two candidates in addition to Wilson-Foley: Justin Bernier and Mark Greenberg, both of whom ran in 2010 but lost the nomination to Caligiuri, who has already announced that he will not run again in 2012.

The Democratic field is still taking shape, although former state Rep. Elizabeth Esty jumped into the race earlier in the week. She served one term in the state House.