LADY MARKBY: Really, now that the House of Commons is trying to become useful, it does a great deal of harm. (1.54)
One of the older characters in the play, Lady Markby's conversation is often a variation on "how things have changed." Here she seems to long for a bygone past when the House of Commons was more ceremonial than effective.
MRS. CHEVELEY. Politics are my only pleasure. (1.84)
Laura, Laura, Laura. (That's Mrs. Cheveley's first name.) It's all about her. Politics, sex, friendship all serve one purpose – securing her comfort and security.
SIR ROBERT CHILTERN. A political life is a noble career! (1.85)
This is early in his conversations with Mrs. Cheveley – before she reminds him of the ignoble moment that bought him this noble political career. One immoral act has enabled him to do a lot of good. The only problem is that she is not willing to forget that original, immoral act.