Evidence simply don't support such claims...
The tax code had only 400 pages in its inception in 1913!
Government spending in the United States currently equals more than forty percent of national income, i.e., the sum of all wages and salaries and profits and interest earned in the country. This is without counting any of the massive off-budget spending such as that on account of the government enterprises Fannie Mae and Freddie Mac. Nor does it count any of the recent spending on assorted "bailouts." What this means is that substantially more than forty dollars of every one hundred dollars of output are appropriated by the government against the will of the individual citizens who produce that output. The money and the goods involved are turned over to the government only because the individual citizens wish to stay out of jail. Their freedom to dispose of their own incomes and output is thus violated on a colossal scale. In contrast, under laissez-faire capitalism, government spending would be on such a modest scale that a mere revenue tariff might be sufficient to support it. The corporate and individual income taxes, inheritance and capital gains taxes, and social security and Medicare taxes would not exist.
There are presently fifteen federal cabinet departments, nine of which exist for the very purpose of respectively interfering with housing, transportation, healthcare, education, energy, mining, agriculture, labor, and commerce, and virtually all of which nowadays routinely ride roughshod over one or more important aspects of the economic freedom of the individual. Under laissez-faire capitalism, eleven of the fifteen cabinet departments would cease to exist and only the departments of justice, defense, state, and treasury would remain. Within those departments, moreover, further reductions would be made, such as the abolition of the IRS in the Treasury Department and the Antitrust Division in the Department of Justice.
The economic interference of today's cabinet departments is reinforced and amplified by more than one hundred federal agencies and commissions, the most well known of which include, besides the IRS, the FRB and FDIC, the FBI and CIA, the EPA, FDA, SEC, CFTC, NLRB, FTC, FCC, FERC, FEMA, FAA, CAA, INS, OHSA, CPSC, NHTSA, EEOC, BATF, DEA, NIH, and NASA. Under laissez-faire capitalism, all such agencies and commissions would be done away with, with the exception of the FBI, which would be reduced to the legitimate functions of counterespionage and combating crimes against person or property that take place across state lines.
To complete this catalog of government interference and its trampling of any vestige of laissez faire, as of the end of 2007, the last full year for which data are available, the Federal Register contained fully seventy-three thousand pages of detailed government regulations. This is an increase of more than ten thousand pages since 1978, the very years during which our system, according to one of The New York Times articles quoted above, has been "tilted in favor of business deregulation and against new rules." Under laissez-faire capitalism, there would be no Federal Register. The activities of the remaining government departments and their subdivisions would be controlled exclusively by duly enacted legislation, not the rule-making of unelected government officials.
And, of course, to all of this must be added the further massive apparatus of laws, departments, agencies, and regulations at the state and local level. Under laissez-faire capitalism, these too for the most part would be completely abolished and what remained would reflect the same kind of radical reductions in the size and scope of government activity as those carried out on the federal level.