The answer to both questions is clear. Congress has ample power to impose such prohibitions upon practically all corporations, including state banks, trust companies and life insurance companies; and evasion may be made impossible. While Congress has not been granted power to regulate directly state banks, and trust or life insurance companies, or railroad, public-service and industrial corporations, except in respect to interstate commerce, it may do so indirectly by virtue either of its control of the mail privilege or through the taxing power.
Practically no business in the United States can be conducted without use of the mails; and Congress may in its reasonable discretion deny the use of the mail to any business which is conducted under conditions deemed by Congress to be injurious to the public welfare. Thus, Congress has no power directly to suppress lotteries; but it has indirectly suppressed them by denying, under heavy penalty, the use of the mail to lottery enterprises. Congress has no power to suppress directly business frauds; but it is constantly doing so indirectly by issuing fraud-orders denying the mail privilege. Congress has no direct power to require a newspaper to publish a list of its proprietors and the amount of its circulation, or to require it to mark paid-matter distinctly as advertising: But it has thus regulated the press, by denying the second-class mail privilege, to all publications which fail to comply with the requirements prescribed.
The taxing power has been resorted to by Congress for like purposes: Congress has no power to regulate the manufacture of matches, or the use of oleomargarine; but it has suppressed the manufacture of the “white phosphorous” match and has greatly lessened the use of oleomargarine by imposing heavy taxes upon them. Congress has no power to prohibit, or to regulate directly the issue of bank notes by state banks, but it indirectly prohibited their issue by imposing a tax of ten per cent. upon any bank note issued by a state bank.