The somewhat sketchy reports that President Trump would support an increase in the federal motor fuels tax came into sharper clarity today after several lawmakers said they were told by the president that he would back a 25-cent-a-gallon hike, to be imposed at one time, and that he would take the heat from his own party to get it accomplished.

The most direct confirmation came from Sen. Thomas D. Carper (D-Del.), the ranking member of the Senate Environment and Public Works Committee, who said that Trump told him and other lawmakers in a recent closed-door meeting that, in Carper's words, the president "would provide the political cover" for the increase, and absorb the pushback from the Republicans who would oppose it.

Speaking at an annual meeting of the American Association of State Highway and Transportation Officials (AASHTO) in Washington, Carper said he and others in the room were stunned by the directness of Trump's statement.

Carper said that after the meeting with Trump, he contacted Transport Secretary Elaine L. Chao, who told him, in Carper's words, that the president "has been talking about this for weeks." The White House has not tried to clarify or tamp down Trump's comments, leaving that exercise to Republican members of Congress, many of whom are in no mood to raise taxes, Carper added.

Chao, who also spoke at the AASHTO event today, did not refer to Trump's purported comments. Nor did she comment on the mechanism for funding transport projects other than to say the process is greatly complicated by burdensome regulations that the Administration is in the process of addressing and, if necessary, repealing.

Federal taxes on diesel fuel and gasoline, which stand at 24.4 cents and 18.4 cents a gallon, respectively, have not been raised since 1993. In that time, about half the states have raised their fuel taxes, some repeatedly. Earlier this year, the U.S. Chamber of Commerce, the nation's largest business trade group, proposed a 25-cent-a-gallon increase, to be phased in over five years or done all at once. The Chamber said that the increase, which would be indexed to inflation and improvements in fuel economy, would raise about $394 billion over 10 years for the beleaguered Highway Trust Fund, which is supported almost exclusively by fuel tax receipts and has been repeatedly been kept afloat by capital infusions from the general treasury.

The White House has proposed a broad infrastructure initiative that would cost $1.5 trillion over 10 years. Of that amount, $200 billion would be directly funded by the federal government, which would qualify as "seed" capital to encouraging $1.3 trillion from states, localities, public-private sector partnerships, and money from budget savings elsewhere in the federal government. The proposal was silent on funding mechanisms, and critics in and out of Congress contend the $1.3 trillion figure is far too daunting for entities outside the federal government to consider.

Rep. Peter A. DeFazio (D-Ore.), ranking member of the House Transportation and Infrastructure (T&I) Committee, said the funding dilemma is amplified by stiff opposition from GOP leaders like Speaker Paul D. Ryan (R-Wis.), Majority Leader Kevin McCarthy (R-Calif.), and Ways and Means Committee Chairman Kevin Brady (R-Texas) to any such large-scale investment. "Unless President Trump makes it clear that he wants to do something, there will be no investment," DeFazio told the AASHTO gathering. "And if there is no investment, there will be no bill."

Rep. Bill Shuster (R-Pa.), chair of the House T&I Committee, acknowledged that Trump seems set on pushing for a 25-cent-a-gallon fuels tax, and that it will be Republicans, not Democrats, who will push back on it. Shuster added that time is of the essence in crafting an ambitious infrastructure measure as proposed by the White House. Should Congress not pass a bill by the end of 2018, progress will likely stall out in 2019, and then face the run-up to the 2020 general election, where little of legislative significance would get done, Shuster warned.

Shuster, who is retiring at the end of his current term, floated the idea of Congress pushing through a bill during the lame-duck session between the midterm elections in November and the start of the 116th Congress in January.