The House Jan-6 investigation committee consists of 9 house representatives, 7 are Democrats, only two are Republicans. Note that the original plan called for 10 members with half from Democrats and half from the Republicans, somehow, it changed to 13 with 8 from Democratic Party and 5 from Republican Party (see Edit at end). Then after House Speaker Nancy Pelosi rejected two of the Republican picks, House Minority leader Kevin McCarthy withdrew all 5 Republican nominees, and the two Republican members were then handpicked by speaker Pelosi.

Why is the imbalance in party participation, given that the Jan-6 riot has occurred in the US Capitol, and is considered an attack on the Constitution of the United States? What is the justification?

Additional note: Both the Republican Representatives, Liz Cheney of WY and Adam Kinzinger of IL, have long been staunch critics of Donald Trump and have voted, in opposition to their party, in favor of the creation of this investigation panel.

Edit:

My original write up claims the "original plan" called for 13 members (8 Democrats and 5 Republicans) was a mistake. The bill passed called for 10 members with equal spilt, but I don't know how and when it had changed to 13 (per the New York Times' article). The turn of events can be a good talking point. Thanks.