The chair of Republicans' House campaign arm indicated Friday that he will not punish conservative outside groups that target Republican incumbent in primaries, drawing a stark contrast with Republicans' more aggressive tack in Senate races.

"My job is to defeat Democrats and elect Republicans, Republicans that are chosen by Republicans in their districts as the nominees," National Republican Congressional Committee Chair Greg Walden said at a Christian Science Monitor breakfast Friday. "That is really where we're focused, and to the extent that we can have our wide range of outside organizations focused on that, we will be more successful at growing our majority."

The Senate counterpart of Walden's group is already fighting back against outside groups who target incumbents in GOP primaries, saying the groups could cost the party its chance to win back Senate control in the 2014 mid-term elections.

House Republican lawmakers deemed too moderate by conservative outside groups, such as the Club For Growth and Heritage Action, are now facing primary challengers recruited and funded by those groups. Many of the incumbents represent safe Republican districts, areas where the party would normally not have spent its money but now must.

A similar dynamic is playing out in Senate races, where groups like the Senate Conservatives Fund have endorsed primary challengers to Republican incumbents, most notably against Senate Minority Leader Mitch McConnell, R-Ky.

But, unlike the NRCC, the National Republican Senatorial Committee recently began punishing consulting and ad firms that do business with the conservative fund.

McConnell charged recently that the SCF "has elected more Democrats than the Democratic Senatorial (Campaign) Committee over the last three cycles."

But Walden, quoting the late conservative writer William F. Buckley, Jr., indicated that he was most concerned with nominating "the most conservative person who can win the general election."