The most practical and real prejudice from this delay is the lost opportunity for concurrent sentences, which "could be irreversibly compromised in [certain] . . . circumstances." US v. Cone, 310 Fed. Appx. 212, 220 (10th Cir 2008). While not necessarily entitled to concurrent sentences, it is often a beneficial term of a plea agreement or may be requested at sentencing. Courts usually have discretion to run sentences concurrently or consecutively. Setser v. US, 132 S.Ct. 1463, 1468 (2012); see 18 USC section 3584.
Two thoughts: On the front end, if your client is in this trap, then the Speedy Trial Act requires the government to act rather than wait. Subsection (j) of 18 USC 3161 provides that when the government attorney knows that the indicted person is serving a different sentence in a penal institution, then the AUSA must "promptly" get the defendant to federal court (probably by writ), or at least file a detainer and notify the defendant of the right to demand a speedy trial. There are some cumbersome procedures outlined, but most likely the attorney can make the demand for the client, triggering the government's obligation to act. (This is different from the Interstate Agreement on Detainers Act).
Second, if the delay has already occurred, dismissal is a debateable (read: unavailable) remedy (see Cone, supra). The more likely avenue of relief is a sentence adjustment under USSG 5G1.3. Subsection C talks about "undischarged term of imprisonment", that is, the remaining portion of the state sentence. But, as usual, the substance is in the application notes,
3.(A) . . . In order to achieve a reasonable incremental punishment for the instant offense and avoid unwarranted disparity, the court should consider the following:
(iii) The time served on the undischarged sentence and the time likely to be served before release,
(v) Any other circumstance relevant to the determination of an appropriate sentence for the instant offense.The court adjusts the federal sentence to account for the delay by subtracting time served on the state sentence from the calculated federal sentence, then ordering the remainder to run concurrently. (Guideline example after the jump). Note the "unwarranted disparity" language from 18 USC 3553(a)(6), which lends statutory authority to the argument.
Again, this is a sentence adjustment, not a departure or variance. This matters for good-time credit purposes, as explained here.
A couple of other notes. In the Application Note 3.(D), in complex situations, the Court may "fashion a sentence of appropriate length and structure it to run in any appropriate manner to achieve a reasonable punishment for the instant offense." Second, remember under Setser, the Court may sentence concurrently or consecutively to an anticipated but not-yet-imposed sentence from another court.
Finally, if the federal court is silent on the concurrent/consecutive issue and your client is not in primary federal custody (the state sentence will be served first), BOP will parsimoniously impose consecutive sentences, even if the state court says the the sentences shall run concurrently. After all, BOP never misses a chance to over-incarcerate.
If the state sentence is relevant conduct and that was the basis for an increase in the guideline offense level (Ch.2) or adjustment (Ch. 3), then,
5G1.3(b)(1) the court shall adjust the sentence for any period of imprisonment already served on the undischarged term of imprisonment if the court determines that such period of imprisonment will not be credited to the federal sentence by the Bureau of Prisons; and
(2) the sentence for the instant offense shall be imposed to run concurrently to the remainder of the undischarged term of imprisonment.(D) Example.--The following is an example in which subsection (b) applies and an adjustment to the sentence is appropriate:>
<The defendant is convicted of a federal offense charging the sale of 40 grams of cocaine. Under § 1B1.3, the defendant is held accountable for the sale of an additional 15 grams of cocaine, an offense for which the defendant has been convicted and sentenced in state court. The defendant received a nine-month sentence of imprisonment for the state offense and has served six months on that sentence at the time of sentencing on the instant federal offense. The guideline range applicable to the defendant is 12-18 months (Chapter Two offense level of level 16 for sale of 55 grams of cocaine; 3 level reduction for acceptance of responsibility; final offense level of level 13; Criminal History Category I). The court determines that a sentence of 13 months provides the appropriate total punishment. Because the defendant has already served six months on the related state charge as of the date of sentencing on the instant federal offense, a sentence of seven months, imposed to run concurrently with the three months remaining on the defendant's state sentence, achieves this result.