Democratic House candidates should skip their party's national convention this September to focus on campaigning in their districts, according to Democratic Congressional Campaign Committee (DCCC) Chairman Steve Israel (N.Y.).

"If they want to win an election, they need to be in their districts," Israel said at the Reuters Washington Summit on Tuesday. 

But Israel stressed that his advice had nothing to do with President Obama's standing nationwide. "I don't care if the president was at 122 percent favorability right now ... I think [candidates] should be in their districts," he added.

Then-DCCC Chairman Chris Van Hollen (Md.) likewise advised candidates in tough races to stay in their districts rather than go to the convention in 2008, when Obama was at the peak of his popularity, much for the same reason.

A number of red-state Democratic lawmakers have already taken that step, saying they will skip their party's convention in Charlotte, N.C., this September.

On Tuesday, Sen. Claire McCaskillClaire McCaskillTechnology's role in human trafficking cannot be ignored Five things to know about Joe Lieberman Senate GOP short on ideas for stabilizing ObamaCare markets MORE (D), one of the president's most prominent surrogates, became the latest to announce that she would not attend the convention. McCaskill is facing a tough reelection bid in GOP-trending Missouri.

McCaskill joins other Dems who say they are skipping the convention, including West Virginia Gov. Earl Ray Tomblin, Sen. Joe ManchinJoe ManchinIn the politics of healthcare reform, past is prologue Dem senator: UK attack shows importance of US intelligence community Heitkamp, Manchin under pressure over GOP regs bill MORE (W.Va.) and Reps. Nick RahallNick RahallWest Virginia is no longer Clinton country Solution needed: Rail congestion is stifling economic growth Lobbying World MORE (W.Va.), Mark Critz (Pa.), Kathy Hochul (N.Y.), Bill Owens (N.Y.) and Jim MathesonJim MathesonWork begins on T infrastructure plan New president, new Congress, new opportunity First black GOP woman in Congress wins reelection MORE (D-Utah).

On the GOP side, a few Republicans, including former Hawaii Gov. Linda Lingle and Rep. Denny Rehberg (Mont.), have said they'll miss their party's convention.

This story was updated at 9:26 a.m.