Arkansas relation to the transaction is constitutionally different from that of New York in the Berwind-White case, though both are the state of the market, because the Berwind-White Company "maintained its sales office in New York City, took its contracts in New York City and made actual delivery in New York City." This "constituted a sale in New York and accordingly we sustained a retail sales tax by New York." So here the company's "offices are maintained in Tennessee, the sale is made in Tennessee, and the delivery is consummated either in Tennessee or in interstate commerce. "The inevi

table conclusion, it seems to me, is that the Court is deciding not only that Arkansas cannot tax the transaction, but that Tennessee can tax it and is the only state which can do so. To put the matter shortly, Arkansas cannot levy the tax because Tennessee can levy it. Hence "for Arkansas to impose a tax on such transaction would be to project its powers beyond its boundaries and to tax an interstate transaction."

This statement of the matter appears to be a composite of due process and commerce clause ideas. If so, it is hard to see why the same considerations do not nullify Iowa's power to levy her tax in the identical circumstances and vest exclusive jurisdiction in Minnesota to tax these transactions. For in the Iowa case the selling corporation maintains its office and place of business in Minnesota, accepts the orders there, and the delivery, which is to carrier or post, is consummated, so far as the record shows, exactly in the manner it is made in the Tennessee-Arkansas transaction. If these facts nullify Arkansas' power to tax the transaction by vesting exclusive jurisdiction in Tennessee, it would seem a fortiori they would nullify Iowa's power and give Minnesota exclusive jurisdiction to tax the transactions there involved. Unless the sheer difference in the terms "sale" and "use," and whatever difference these might make as a matter of legislative selec

tion of the transactions which are to bear the tax, are to control upon the existence of the power to tax, the result should be the same in both cases.

Merely as a matter of due process, it is hard to see why any of the four states cannot tax the transactions these cases involve. Each has substantial relations and connections with the transaction, the state of market not less in either case than the state of origin. It "sounds better" for the state of origin to call its tax a "sales tax" and the state of market to name its tax a "use tax." But in the Berwind-White case the latter's "sales tax" was sustained, where it is true more of the incidents of sale conjoined with the location of the place of market than do in either No. 311 or No. 441. If this is the distinguishing factor, as it might be for selecting one of the two connected jurisdictions for exclusive taxing power, it is not one which applies to either of these transactions. The identity is not between the Dilworth case and Berwind-White. It is rather between Dilworth and General Trading, with BerwindWhite differing from both. And, so far as due process alone is concerned, it should make no difference whether the tax in the one case is laid by Arkansas or Tennessee and in the other by Iowa or Minnesota. Each state has a sufficiently substantial and close connection with the transaction, whether by virtue of tax benefits conferred in general police protection and otherwise or on account of ideas of territorial sovereignty concerning occurrence of "taxable incidents" within its borders, to furnish the due process foundation necessary to sustain the exercise of its taxing power. Whether it exerts this by selecting for "impingement" of the tax some feature or incident of the transaction which it denominates "sale" or "use" is both illusory and unimportant in any bearing upon its constitutional authority as a matter of due process. If this has any substantive effect, it is merely one of legislative intent in selecting the transactions to bear the tax and thus

fixing the scope of its coverage, not one of constitutional power. "Use" may cover more transactions with which a state has due process connections than "sale." But whenever sale occurs and is taxed the tax bears equally, in final incidence of burden, upon the use which follows immediately upon it.

The great difficulty in allocating taxing power as a matter of due process between the state of origin and the state of market arises from the fact that each state, considered without reference to the other, always has a sufficiently substantial relation in fact and in tax benefit conferred to the interstate transaction to sustain an exertion of its taxing power, a fact not always recognized. And from this failure, as well as from the terms in which statutes not directed specifically to reaching these transactions are cast, comes the search for some "taxable incident taking place within the state's boundaries" as a hook for hanging constitutionality under due process ideas. "Taxable incident" there must be. But to take what is in essence and totality an interstate transaction between a state of origin and one of market and hang the taxing power of either state upon some segmented incident of the whole and declare that this does or does not "tax an interstate transaction" is to do two things. It is first to ignore that any tax hung on such an incident is levied on an interstate transaction. For the part cannot be separated from the whole. It is also to ignore the fact that each state, whether of origin or of market, has by that one fact alone a relation to the whole transaction so substantial as to nullify any due process prohibition. Whether the tax is levied. on the "sale" or on the "use," by the one state or by the other, it is in fact and effect a tax levied on an interstate transaction. Nothing in due process requirements prohibits either state to levy either sort of tax on such transactions. That Tennessee therefore may tax this transaction by a sales tax does not, in any proper conception of due process, deprive Arkansas of the same power.

When, however, the issue is turned from due process to the prohibitive effect of the commerce clause, more substantial considerations arise from the fact that both the state of origin and that of market exert or may exert their taxing powers upon the interstate transaction. The long history of this problem boils down in general statement to the formula that the states, by virtue of the force of the commerce clause, may not unduly burden interstate commerce. This resolves itself into various corollary formulations. One is that a state may not single out interstate commerce for special tax burden. McGoldrick v. BerwindWhite Coal Mining Co., 309 U. S. 33, 55-56. Nor may it discriminate against interstate commerce and in favor of its local trade. Welton v. Missouri, 91 U. S. at 275; Guy v. Baltimore, 100 U. S. 434; Voight v. Wright, 141 U. S. 62. Again, the state may not impose cumulative burdens upon interstate trade or commerce. Gwin, White & Prince v. Henneford, 305 U. S. 434; Adams Mfg. Co. v. Storen, 304 U. S. 307. Thus, the state may not impose certain taxes on interstate commerce, its incidents or instrumentalities, which are no more in amount or burden than it places on its local business, not because this of itself is discriminatory, cumulative or special or would violate due process, but because other states also may have the right constitutionally, apart from the commerce clause, to tax the same thing and either the actuality or the risk of their doing so makes the total burden cumulative, discriminatory or special.2

In these interstate transactions cases involving taxation by the state of origin or that of market, the trouble arises, under the commerce clause, not from any danger that either tax taken alone, whether characterized as "sales" or

2 Cf. the opinion of the Chief Justice in Northwest Airlines v. Minnesota, ante, p. 308.

"use" tax, will put interstate trade at a disadvantage which will burden unduly its competition with the local trade. So long as only one tax is applied and at the same rate as to wholly local transactions, no unduly discriminatory clog actually attaches to the interstate transaction of business.

The real danger arises most obviously when both states levy the tax. Thus, if in the instant cases it were shown that, on the one hand, Arkansas and Iowa actually were applying a "use" tax and Tennessee and Minnesota a "sales" tax, so that in each case the interstate transaction were taxed at both ends, the heavier cumulative burden thus borne by the interstate business in comparison with the local trade in either state would be obvious. If in each case the state of origin were shown to impose a sales tax of three per cent and the state of market a use tax of the same amount, interstate transactions between the two obviously would bear double the local tax burden borne by local trade in each state. This is a difference of substance, not merely one of names, relevant to the problem created by the commerce clause, though not to that of "jurisdiction" under due process conceptions. And the difference would be no less substantial if the taxes levied by both the state of origin and that of market were called "sales" taxes or if, indeed, both were called "use" taxes.

The Iowa tax in No. 441 avoids this problem by allowing credit for any sales tax shown to be levied upon the transaction whether in Iowa or elsewhere. Clearly therefore that tax cannot in fact put the interstate transaction at a tax disadvantage with local trade done in Iowa or elsewhere.3

However, the Arkansas tax in No. 311 provides for no such credit. But in that case there is no showing that Tennessee actually imposes any tax upon the transaction.

8 Cf. text infra at note 4 et seq.